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Titanocene dichloride, [Ti]Cl2 (1) ([Ti] = Ti(η5-C5H4SiMe3)2), with one equiv. of the lithium thiolates LiSCHR-2-cC4H3S (2a, R = H; 2b, R = Me) gave the appropriate [Ti](Cl)(SCHR-2-cC4H3S) compounds (3a, R = H; 3b, R = Me) under mild reaction conditions. Further treatment of 3a,b with another equiv. of thiolates 2a,b produced the respective bis(thiolates) species [Ti](SCHR-2-cC4H3S)2 (4a,b). Titanocenes 4a,b are also accessible, when 1 is reacted with 2a,b in a 1:2 M ratio. The hydrolysis reaction of 4a,b produced the titanoxane cluster 5, consisting of a [Ti′]6O9 cage ([Ti′] = Ti(η5-C5H4SiMe3)) with a silsesquioxane analog structure. The molecular structure of 5 in the solid state is the first example of a trigonal prismatic Ti6-polyhedron. Upon treatment of 4a,b with MCl2 (M = Pd, Pt), aiming to obtain heterobimetallic coordination complexes, however, either 1 or 3a,b were formed, depending on the reaction conditions. All the compounds have been characterized by elemental analysis, IR, NMR (1H, 13C{1H}) spectroscopy and mass-spectrometry.

Treatment of Ti(η 5-1-SiMe3C9H6)Cl3 (1) with LiOR (2a, R = 2,6-tBu2C6H3; 2b, R = 2,6-Ph2C6H3; 2c, R = iC3H7; 2d, R = tC4H9) in a 1:1 M ratio produced half-sandwich compounds Ti(η 5-1-SiMe3C9H6)(Cl)2(OR) (3a, R = 2,6-tBu2C6H3; 3b, R = 2,6-Ph2C6H3; 3c, R = iC3H7; 3d, R = tC4H9) in high yield. Compounds 3c,d were also accessible, when 1 was reacted with a onefold excess of HOR (2c, R = iC3H7; 2d, R = tC4H9) in refluxing benzene. The molecular structure of 3b in the solid state was determined by single-crystal X-ray diffraction studies, confirming the piano-stool geometry. Quantum chemical calculations at the B3LYP/6-31g(d)+LANL2DZ level of theory were carried out for 1 and 3a–d in order to better understand and rationalize the nature of bonding and thus demonstrate the effect of different substituents on the structural and electronic properties in these compounds. The studies reveal a high electron density on the Ti(IV) ion for 3c and 3d as compared to 3a and 3b, and also showed the possibility of controlling and fine tuning the electron density on the Ti(IV) ion through the introduction of different alkyloxy or aryloxy substituents.

1,4-Diazidobuta-1,3-dienes (Z,Z)-10, 17, and 21 were photolyzed and thermolyzed to yield the pyrid-azines 13, 20, and 23, respectively. To explain these aromatic final products, the generation of highly strained bi-2H-azirin-2-yls 12, 19, and 22 and their valence isomerization were postulated. In the case of meso- and rac-22, nearly quantitative formation from diazide 21, isolation as stable solids, and complete characterization were possible. On the thermolysis of 22, aromatization to 23 was only a side reaction, whereas equilibration of meso- and rac-22 and fragmentation, which led to alkyne 24 and acetonitrile, dominated. Prolonged irradiation of 22 gave mainly the pyrimidine 25. The change of the configuration at C-2 of the 2H-azirine unit was observed not only in the case of bi-2H-azirin-2-yls 22 but also for simple spiro-cyclic 2H-azirines 29 at a relatively low temperature (75 degrees C). The fragmentation of rac-22 to give alkyne 24 and two molecules of acetonitrile was also studied by high-level quantum chemical calculations. For a related model system 30 (methyl instead of phenyl groups), two transition states TS-30-31 of comparable energy with multiconfigurational electronic states could be localized on the energy hypersurface for this one-step conversion. The symmetrical transition state complies with the definition of a coarctate mechanism.

The synthesis and properties of heterobimetallic Ti–Cd complexes of type {[Ti](μ-η1:η2–C CR)2}CdX2 ([Ti] = Ti(η5–C5H4SiMe3)2; R = SiMe3: 3a, X = Cl; 3b, X = Br; 3c, X = I; R = Fc: 3d, X = Br; Fc = Fe(η5–C5H4)(η5–C5H5) is reported. These compounds were accessible by treatment of [Ti](C CR)2 (1a, R = SiMe3; 1b, R = Fc) with the cadmium salts CdX2 (2a, X = Cl; 2b, X = Br; 2c, X = I) in a 1:1 M ratio in diethyl ether. Dissolving, for example, 3b in tetrahydrofuran afforded coordination polymer [Cd(μ-Br)2(thf)2]n (4) along with the tweezer molecule 1a. Treatment of 3b with two equiv of LiC CFc (5) gave {[Ti](μ-η1:η2–C CSiMe3)2}Cd(C CFc)2 (6) which eliminated at ambient temperature the all-carbon buta-1,3-diyne FcC C–C CFc (7) producing 1a and elemental Cd. The same reaction behavior was observed, when 2b was reacted with 5. The thus obtained bis(alkynyl) cadmium complex Cd(C CFc)2 (8) is redox-active at low temperature producing 7 and Cd(0). When mercury halides HgX2 (9a, X = Cl; 9b, X = Br) are used, then the titanocene dihalides [Ti]X2 (10a, X = Cl; 10b, X = Br) together with Me3SiC C–C CSiMe3 (11) and Hg(0) were formed. Nevertheless, mercury acetylides were available by treatment of Hg(OAc)2 (12) with HC CFc (13) in a 1:2 M ratio. Thus obtained Hg(C CFc)2 (14) gave with [CuBr] (15) coordination polymer [{Hg(η2-C CFc)2}(Cu2(μ-Br)2]n (16), while with [AgPF6] oxidation of the ferrocenyl moieties took place affording dicationic [Hg(C CFc)2]2+ (18). The structures of 3b and 4 in the solid state are reported. Compound 3b shows the typical characteristics for heterobimetallic organometallic π-tweezer complexes with cadmium in a tetrahedral environment, while 4 corresponds to a one-dimensional coordination polymer in which the Cd(II) ions are linked in a edge-sharing fashion by bromide bridges in the pseudo-equatorial plane. The appropriate tetrahydrofuran molecules are completing the pseudo-octahedral coordination sphere at cadmium. The cyclic voltammogram of 14 is reported showing a single reversible redox event at E0 = 0.108 V with ΔEp = 76 mV indicating that there is no communication between the Fc termini along the mercury acetylide unit.

Individual synthetic routes to heterobimetallic Ti(IV)–Ag(I) acetylides of type {[Ti](μ-σ,π-C CR1)2}AgC CR2 ([Ti] = (η5-C5H4SiMe3)2Ti: R1 = SiMe3: 6, R2 = SiMe3; 7, R2 = Ph. R1 = tBu: 8, R2 = SiMe3; 9, R2 = Ph. [Ti] = (η5-C5H5)2Ti): 10, R1 = tBu, R2 = SiMe3) including (i) the reaction of {[Ti](μ-σ, π-C CR1)2}AgNO3 ([Ti] = (η5-C5H4SiMe3)2Ti): 1, R1 = SiMe3; 2, R1 = tBu. [Ti] = (η5-C5H5)2Ti: 3, R1 = tBu) with LiC CR2 (4, R2 = SiMe3; 5, R2 = Ph) and (ii) treatment of [Ti](C CSiMe3)2 ([Ti] = (η5-C5H4SiMe3)2Ti) (11) with [AgC CR2] (12, R2 = SiMe3; 13, R2 = Ph) are described. The reactions of 1–3 with 4 or 5 appeared to be sensitive towards stoichiometry because an excess of 4 or 5 resulted in the formation of [(Ag(C CR2)2)Li(OEt2)]n (14) and [Ti](C CR1)2. Coordination polymer 14 is also accessible, when, for example, [AgC CSiMe3] (12) is treated with 1 eq. of LiC CSiMe3 (4) in diethyl ether. The titanium(IV)–silver(I) acetylides 6–10 are stable in the dark and at low temperature, while on exposure to light and on heating they decompose to give R2C C–C CR2 together with [Ti](C CR1)2 and elemental silver. Complexes 6–10 contain a mono-nuclear AgC CR2 entity stabilized by the chelate-bonded organometallic π-tweezer molecule [Ti](C CSiMe3)2, which was evinced by structure determination of 7 in the solid state. In 14 linear [Me3SiC C–Ag–C CSiMe3]− units are connected by [Li(OEt2)]+ building blocks forming a coordination polymer.

Three different methods to prepare 1,4-diazidobuta-1,3-dienes are presented: nucleophilic substitution of electron-poor dichlorinated substrates, nucleophilic addition of hydrazoic acid at an electron-deficient diallene, and a sequence of prototropic isomerizations of propargyl sulfones followed by nucleophilic additions. In all cases, isolation and assignment of the diastereomeric products was possible, and some sequential reactions, such as reduction or 1,3-dipolar cycloaddition of the azido groups, were performed.

The thermal reaction of the dinuclear complex [Ru2(CO)4(O2CH)2(PCy2H)2] with molecular hydrogen in cyclohexane afforded the tetranuclear clusters [H4Ru4(CO)8(PCy2)4] (64e) and [H5Ru4(CO)8(PCy2)3] (62e), both of which have a square-planar arrangement of the metal framework.

Alkyloxy- and aryloxy-functionalized titanocenes of type [Ti](Cl)(OR) (R = Me (2), CH2PPh2 (3), CH2Fc (4), C6H5 (5), C6H4-4-C N (6), C6H4-4-NO2 (7), C6H4-4-Me (8), C6H4-4-OMe (9), C6H4-4-C(O)Me (10), C6H4-4-CO2Me (11), C6H4-3-NO2 (12); [Ti] = (η5-C5H4SiMe3)2Ti; Fc = (η5-C5H4)(η5-C5H5)Fe) were synthesized by the reaction of [Ti]Cl2 (1) with ROH in a 1:1 molar ratio and in presence of Et2NH. Diaryloxy-titanocenes (e.g., [Ti](OC6H4-4-NO2)2 (13)) are accessible, when the ratio of 1 and ROH is changed to 1:2. This synthesis methodology also allowed the preparation of dinuclear complexes of composition ([Ti](Cl))2(μ-OC6H4O) (14) and ([Ti](Cl)(μ-OC6H4-4))2 (15) by the reaction of 1 with hydroquinone or 1,1′-dihydroxybiphenyl in a 2:1 stoichiometry. Cyclic voltammetric studies show the characteristic [Ti(IV)/Ti(III)] reductions. It was found that the potentials of the alkyloxy titanocenes 2–4 do not differ, while for the aryloxy-titanocenes 5–15 the reduction potentials correlate linearly with the σp/m Hammett substituent constants showing a strong influence of the substituents on the electron density at titanium. The structures of titanocenes 4, 5, 9, and 11–13 in the solid state are reported. Typical for these organometallic sandwich compounds is a distorted tetrahedral coordination geometry around titanium with D1–Ti–D2 angles (D1, D2 = centroids of the cyclopentadienyl ligands) of ca. 130 °. In comparison to FcCH2O-functionalized 4, for the aryloxy-titanocenes 5, 9, and 11–13 a significant larger Ti–O–C angle was found confirming electronic interactions between the titanium atom and the appropriate aryl group.

Complexes of type { cis -[Pt](μ-σ,π-C CPh) 2 }AgX ( 3a , [Pt] = (bipy′)Pt, X = FBF 3 ; 3b , [Pt] = (bipy′)Pt, X = FPF 5 ; 3c , [Pt] = (bipy)Pt, X = OClO 3 ; 3d , [Pt] = (bipy′)Pt, X = BPh 4 ; bipy′ = 4,4′-dimethyl-2,2′-bipyridine; bipy = 2,2′-bipyridine) are accessible by combining cis -[Pt](C CPh) 2 ( 1a , [Pt] = (bipy′)Pt; 1b , [Pt] = (bipy)Pt) with equimolar amounts of [AgX] ( 2a , X = BF 4 ; 2b , X = PF 6 ; 2c , X = ClO 4 ; 2d , X = BPh 4 ). In 3a – 3d the platinum(II) and silver(I) ions are connected by σ- and π-bonded phenyl acetylide ligands. When the molar ratio of 1 and 2 is changed to 2:1 then trimetallic [{ cis -[Pt](μ-C CPh) 2 } 2 Ag]X ( 8a , [Pt] = (bipy)Pt, X = BF 4 ; 8b , [Pt] = (bipy′)Pt, X = PF 6 ; 8c , [Pt] = (bipy)Pt, X = BF 4 ) is produced. The solid state structure of 8a was determined by single X-ray crystal structure analysis. In 8a the silver(I) ion is embedded between two parallel oriented cis -[Pt](C CPh) 2 units. Within this structural arrangement the phenyl acetylides of individual [Pt](C CPh) 2 entities possess a μ-bridging position between Pt(II) and Ag(I). In addition, a very weak dative Pt → Ag interaction is found (Pt–Ag 2.8965(3) A). The respective silver carbon distances Ag–C α (2.548(7), 2.447(7) A) and Ag–C β (3.042(7), 2.799(8) A)(PtC α C β Ph) confirm this structural motif. Complexes 8a – 8c isomerize in solution to form trimetallic [{ cis -[Pt](μ-σ,π-C CPh) 2 } 2 Ag]X ( 9a , [Pt] = (bipy)Pt, X = BF 4 ; 9b , [Pt] = (bipy′)Pt, X = PF 6 ; 9c , [Pt] = (bipy)Pt, X = ClO 4 ). In the latter molecules the organometallic cation [{ cis -[Pt](μ-σ,π- C CPh) 2 } 2 Ag] + is set-up by two nearly orthogonal positioned [Pt](C CPh) 2 entities which are hold in close proximity by the group-11 metal ion. Within this assembly all four PhC C units are η 2 -coordinated to silver(I). A possible mechanism for the formation of 9 is presented.

Indenyl-Titaniumchlorides: Ethene-Polymerization and Structure-Reactivity Studies The halfsandwich complexes [(η5-C9H7)TiCl3] (3a), [(η5-Me3Si-1-C9H6)TiCl3] (3b), [(η5-Me-1-C9H6)TiCl3] (3c), [(η5-Me2-4,7-C9H5)TiCl3] (3d), [(η5-Me3Si-2-C9H6)TiCl3] (3e), [(η5-Me2–1,3-C9H5)TiCl3] (3f), [(η5-(CH2)3–5,6-C9H5)TiCl3] (4), and [(η5-(CH2)3–1,7-C9H5)TiCl3] (5) are accessible by reacting the in position 1 or 3 Me3Si-functionalized appropriate indenes with TiCl4. CG-TiCl2 compounds (CG = Constraint Geometry) can be synthesized by the subsequent reaction of Br-2-C9H7 (6a), Br-2-Me2-1,3-C9H5 (6b) and Br-2-(CH2)3-5,6-C9H5 (6c), respectively, with magnesium in presence of Me2SiCl2 to give the respective Me2SiCl-functionalized indenes which further react with an excess of H2NtBu to afford tBuHN-SiMe2-2-C9H7 (8a), tBuHN-2-Me2-1,3-C9H5 (8b) and tBuHN–2-(CH2)3-5,6-C9H5 (8c). The latter species produce on their consecutive reaction with nBuLi, [TiCl3·3Thf] and PbCl2 the titanium CG-complexes [(η5-SiMe2NtBu-2-C9H6)TiCl2] (9a), [(η5-Me2-1,3-SiMe2NtBu-2-C9H4)TiCl2] (9b), and [(η5-Me2SiNtBu-2-(CH2)3-5,6-C9H4)TiCl2] (10). The same synthesis protocol allows the preparation of [(η5-Me2SiNtBu-1-Me3Si-2-C9H5)TiCl2] (12) a CG complex in which the Me2SiNtBu unit is located in position 1. The polymerization of ethene by using 3–5 and 9–12 and MAO (MAO = methylaluminoxane) as cocatalyst is described to show if a strong activity correlation between 3–5 and 9–12 exists. In order to optimize the catalytic activity of 3–5 the electronic (cyclic voltammetry, UV-Vis spectroscopy) and steric properties (Multiple Overlap Solid Angle) of these species were analyzed. Based on the obtained data, semi-empirical structure-activity models for 3–5 are proposed to obtain an optimized substituent pattern for the indenyl moiety. Substituents in position 1 or 4 of the appropriate indenyl π-perimeters show a strong bathochromic (+M) and electro-neutral to electro-negativ effect (0/-I).

Heterobimetallic {cis-[Pt](μ-σ,π-C CPh)2}[Cu(N CMe)]BF4 (3a: [Pt] = (bipy)Pt, bipy = 2,2′-bipyridine; 3b: [Pt] = (bipy′)Pt, bipy′ = 4,4′-dimethyl-2,2′-bipyridine) is accessible by the reaction of cis-[Pt](C CPh)2 (1a: [Pt] = (bipy)Pt, 1b: [Pt] = (bipy′)Pt]) with [Cu(N CMe)4]BF4 (2). Substitution of N CMe by PPh3 (4) can be realized by the reaction of 3a with 4, whereby [{cis-[Pt](μ-σ,π-C CPh)2}Cu(PPh3)]BF4 (5) is formed. On prolonged stirring of 3 and 5, respectively, N CMe and PPh3 are eliminated and tetrametallic {[{cis-[Pt](η2-C CPh)2}Cu]2}(BF4)2 (6) is produced. Addition of an excess of N CMe to 6 gives heterobimetallic 3a. When instead of N CMe or PPh3 chelating molecules such as bipy (7) are reacted with 3a then the heterobimetallic π-tweezer molecule [{cis-[Pt](μ-σ,π-C CPh)2}Cu(bipy)]BF4 (8) is formed. Treatment of 8 with another equivalent of 7 produced [Cu(bipy2)]BF4 (9) along with [Pt](C CPh)2. However, when 3b is reacted with 1b in a 1:1 molar ratio then 10 and 11 of general composition [{[Pt](C CPh)2}2Cu]BF4 are formed. These species are isomers and only differ in the binding of the PhC C units to copper(I). A possible mechanism for the formation of 10 and 11 is presented. The solid state structures of 6, 10 and 11 are reported. In 11 the [{cis-[Pt](μ-σ,π-C CPh)2}2Cu]+ building block is set-up by two nearly orthogonal positioned bis(alkynyl) platinum units which are connected by a Cu(I) ion, whereby the four carbon–carbon triple bonds are unsymmetrical coordinated to Cu(I). In trimetallic 10 two cis-[Pt](C CPh)2 units are bridged by a copper(I) center, however, only one of the two PhC C ligands of individual cis-[Pt](C CPh)2 fragments is η2-coordinated to Cu(I) giving rise to the formation of a [(η2-C CPh)2Cu]+ moiety with a linear alkyne–copper–alkyne arrangement (alkyne = midpoint of the C C triple bond). In 6 two almost parallel oriented [Pt](C CPh)2 planes are linked by two copper(I) ions, whereby two individual PhC C units, one associated with each Pt building block, are symmetrically π-coordinated to Cu.

Inclusion properties of a new family of clathrate hosts (1–4) containing two 9-hydroxy-9-fluorenyl units or chloro-, bromo- and t-butyl-substituted derivatives of this group attached in the 3,3′-position to a basic 2,2′-binaphthyl construction element are reported (115 examples of clathrates). The crystal structures of six selected clathrates, involving dimethylsulfoxide, cyclopentanol, diethylether, benzylamine, chloroform and acetone as the guest, have been determined by X-ray diffraction, showing varied modes of supramolecular interaction dependent on the host and guest constitutions, while the formation of an intramolecular hydrogen bond between the hydroxy groups of the fluorenol units is a common structural feature (except in 3a) controlling twisted conformation of the host molecules.

Tri-n-Butyl-Phosphane Silver(I) Complexes with Carboxylate-, Tropolonate- or N-Hydroxyphthalimide Building Blocks; Synthesis and their Use as Spin-on Precursors Treatment of AgNO3 (1) with one equivalent of HX (2a, X = trop; 2b, X = phthal; trop = troponolate; phthal = N-hydroxy-phthalimide anion) in presence of NEt3 affords the silver(I) salts [AgX] (3a, X = trop; 3b, X = phthal) in quantitative yield. When instead of 2a and 2b oxalic acid (4a) or quadratic acid (1,2-dihydroxycyclobutene-3,4-dione) (4b) are reacted with 1 under similar reaction conditions, then the corresponding disilver salts [Ag2E] (5a, E = ox; 5b, E = quad; ox = oxalate; quad = quadratic acid dianion) are accessible in excellent yield. The reaction of 3 and 5 with m equivalents of nBu3P (6) produces the phosphane silver(I) complexes (nBu3P)mAgX (m = 1: 7a, X = trop; 7b, X = phthal; m = 2: 8a, X = trop; 8b, X = phthal) and (nBu3P)mAg-E-Ag(PnBu3)m (m = 1: 9a, E = ox; 9b, E = quad; m = 2: 10a, E = ox; 10b, E = quad; m = 3: 11a, E = ox; 11b, E = quad), which can be isolated after appropriate work-up as colourless (9–11), yellow (7a, 8a) or red-purple (7b, 8b) species. The solid-state structures of 7b and 9a are reported. Complex 7b exists of two (nBu3P)Ag(phthal) units in which the oxygen atoms of the N-hydroxyphthalimide anions are μ-bridging both silver atoms. The thus formed 4-membered Ag2O2 cycle is planar and the silver atoms show the coordination number 3. Complex 9a exhibits a planar dinuclear structure with the anticipated oxalate building block in a μ-1,2,3,4 bridging mode. As typical for 7b also for 9a a tricoordinated silver(I) ion is present, whereby the phosphanes act as neutral capping ligands. The thermal behaviour of selected species (7b, 8b, 9a, 10a, 11a and 11b) was studied by applying thermogravimetry. The decomposition of the latter complexes starts between 100–160 °C and is completed in the region of 350–400 °C. One – four decomposition steps are typical. The decomposition of 9a was studied in detail. Elimination of nBu3P occurs at first, while loss of CO2 from in-situ generated [Ag2ox] gives elemental silver. For that reason, 9a was used as spin-on precursor in the deposition of silver on TiN-coated oxidized silicon wafers. REM studies showed that closed and homogeneous silver layers were formed. The resistivity was determined to 3.4 μΩcm.

A new onium salt host molecule 1 featuring a spiro-type ammonium backbone was synthesized and shown to form a crystalline inclusion compound with chloroform, 1 · chloroform (1:2), the crystal structure of which is reported. The host molecular interactions including C–H···Br, Cl···Cl and aromatic stacking contacts are typical of the packing structure.

The reaction of [Ti](C CR)2 {[Ti] = (η5-C5H4SiMe3)2Ti; 1a, R = Fc, Fc = (η5-C5H4)Fe(η5-C5H5); 1b, R = Ph} with MX {2a, MX = [Cu(N CCH3)4]BF4; M = Ag; 2b, X = ClO4; 2c, X = NO3} in a 2:1 molar ratio produces the trinuclear heterobimetallic (Ti2M) or heptanuclear heterotrimetallic (Ti2MFe4) complexes [{[Ti](μ-σ,π-C CR)2}2M]X (R = Fc: 3a, M = Cu, X = BF4; 3b, M = Ag, X = ClO4. R = Ph: 3c, M = Cu, X = BF4; 3d, M = Ag, X = ClO4: 3e, M = Ag, X = NO3) in high yield. Complexes 3c–3e are also accessible, when {[Ti](μ-σ,π-C CPh)2}MX (M = Cu: 4a, X = FBF3; M = Ag: 4b, X = OClO3; 4c, X = ONO2) is reacted with one equivalent of 1b. Transferring this reaction scheme to [Ti](C CSiMe3)2 (1c) only the formation of the heterobimetallic tweezer complex {[Ti](μ-σ,π-C CSiMe3)2}MX {4d, MX = [Cu(N CCH3)]BF4; 4e, MX = AgOClO3} is observed which is attributed to the bulkiness of the acetylide-bound Me3Si group. The solid-state structure of 3e is reported. In 3e, two [Ti](C CPh)2 tweezer moieties are chelate-bound by their carbon–carbon triple bonds to a silver(I) ion, resulting in a pseudo-tetrahedral environment at the group-11 metal. NO 3 - is acting as counter-ion to cationic [{[Ti](C CPh)2}2Ag]+. Additionally, the result of cyclic voltammetric studies on [{[Ti](μ-σ,π-C CPh)2}2Cu]BF4 (3c) is reported.

Zusammenfassung Die Darstellung der Titelverbindung { trans -(Ph 3 P) 2 Pt[(η 2 -CCPh)CuX] 2 } n ( 3a , X=Cl; 3b , X=Br) gelingt durch die Umsetzung von trans -(Ph 3 P) 2 Pt(CCPh) 2 ( 1 ) mit zwei Aquivalenten an [CuX] ( 2a , X=Cl; 2b , X=Br). Das Reaktionsverhalten von 3b gegenuber organischen Chelatmolekulen wird vorgestellt. Bringt man 3b mit z. B. 2,2 ′ -Bipy ( 4 ) zur Reaktion, so kann neben 1 der Kupfer(I)-Chelat-Komplex [(Bipy)CuBr] 2 ( 6 ) isoliert werden. Im Vergleich dazu reagiert 3b mit dem Silber(I)-Salz [AgNO 3 ] ( 5a ) zu trans -(Ph 3 P) 2 Pt[(η 2 -CCPh)CuNO 3 ] 2 ( 7 ), einer Verbindung, in der jede der beiden Phenylethinylliganden an eine Silber(I)-Nitrat-Einheit η 2 -koordiniert. Trimetallisches 7 ist auch durch die Umsetzung von 1 mit zwei Aquivalenten an [Cu(NCMe) 4 ]NO 3 ( 5b ) zuganglich. Die Festkorperstrukturen von 3b und 7 werden vorgestellt. Das Koordinationspolymer 3b kristallisiert in der triklinen Raumgruppe P 1 mit den Zellparametern a =11.5958(3) A, b =13.3491(3) A, c =15.4875(4) A, α =81.755(1)°, β=87.3240(1)°, γ =85.4720(1)°, V =2363.66(10) A 3 , Z =2 und ρ =1.818 g mol −1 . Komplex 7 : monokline Raumgruppe P 2 1 / n mit a =9.8971(1), b =14.2324(3), c =16.6957(2) A, β=105.478(1)°, V =2266.46(6) A 3 , Z =2 und ρ =1.719 g mol −1 . In 3b liegt eine lineare polymere Struktur vor, in der zwei voneinander kristallographisch unabhangige trans -Pt(CCPh) 2 Einheiten durch viergliedrige Cu 2 (μ-Br) 2 Ringe miteinander verbruckt sind, wobei die entsprechenden PhCC Einheiten an die Kupfer(I)-Zentren η 2 -koordinieren. In 7 ist dagegen jede der beiden PhCC-Einheiten an eine einkernige CuNO 3 -Gruppe π-gebunden, wobei der NO 3 -Rest als Chelatligand uber zwei Sauerstoffatome an das Kupfer(I) bindet.

Controlled photolytic CO-substitution reaction of the organoiron thiocarboxylate complexes CpFe(CO)2SCOR (R=CH3, 2-NO2C6H4, 4-NO2C6H4, 3,5-(NO2)2C6H3) with diphosphines (Ph2P(CH2)nPPh2) [n=1 (dppm), n=2 (dppe)] at 0 °C using 1:1 (metal:ligand) molar ratio afforded exclusively the monosubstituted complexes CpFe(CO)(Ph2P(CH2)nPPh2)SCOR. The complex CpFe(CO)(Ph2PCH2P=S(Ph)2)SCO-3,5-(NO2)2C6H3 has been prepared and its X-ray structure was determined.

Dinuclear nickel(II) and palladium(II) complexes with Schiff-base ligands (derived form salicylaldehyde condensed with 2-amino-1-alcohols or from 2-hydroxy-5-methylisophthaldialdehyde and pyridine-2-carboxaldehyde condensed with semicarbazide, thiosemicarbazide, carbonodihydrazide, or thiocarbonodihydrazide) can be activated with the co-catalysts methylalumoxane (MAO) or tris(pentafluorophenyl)borane/triethylaluminium, B(C6F5)3/AlEt3 for the vinyl/addition polymerization of norbornene to reach activities of up to 2.4 · 107 gpolymer/mol(metal)·h (molar ratios metal:AlMAO = 1:100, metal:borane:AlEt3 = 1:9:10). Polymer characterization by GPC gave molar mass distributions of Mw/Mn ≈ 2, thereby indicating a coordination polymerization with a single-site character of the active species.

The neutral mononuclear osmium(VI) dioxo complexes cis-[OsO2Cl2L2] [L=pyz (3a), L=cpy (3b); pyz=pyrazine, cpy=4-cyanopyridine] (cis refers to the Cl functionality) are accessible by treatment of OsO4 (1) with pyz (2a) or cpy (2b) in a 1:2 molar ratio in a methanol/acetone mixture in presence of HCl. Within this reaction HCl acts as chloride source for the transition metal osmium. When 3a is reacted with 2 equiv. of [Pd(dppp)](OTf)2 (4) (OTf=OSO2CF3, dppp=diphenylphosphinopropane) homobimetallic [Pd(dppp)(μ-Cl)]2(OTf)2 (5) along with pyz (2a) is produced upon precipitation of OsO2. A similar reaction behaviour is observed, when 3a is treated with Mo(CO)5(Thf) (Thf=tetrahydrofuran) (6), since mono- and bimetallic complexes of structural type Mo(CO)5(pyz) (7), [Mo(CO)5]2(μ-pyz) (8) and Mo(CO)5Cl (9) and further chloride-containing molybdenum species are formed. These results show that 3a acts, both as chloride (complexes 5 and 9) and pyz (complexes 7 and 8) transfer reagent, whereby redox processes play a decisive role. The reaction of 1 with Hpz (Hpz=pyrazole) (10) leads to different coordination complexes depending on the acid used: While 1 affords with 10 in a 1:2 molar ratio in presence of HCl a trans/cis mixture of mononuclear neutral [OsO2Cl2(Hpz)2] (11), it is found that, when HNO3 is used instead of HCl, the cationic mono- and homobimetallic osmium(VI) dioxo complexes [OsO2(Hpz)4](NO3)2 (12) and [OsO2(Hpz)2(μ-pz)]2(NO3)2 (13) (pz=pyrazolate) are produced. This different chemical behaviour will be discussed in detail. The X-ray structures of 3a, 3b and 11– 13 have been determined. Crystals of 3a are monoclinic, space group P21/n, with a=11.3700(3), b=9.2039(3), c=12.1107(4) A, β=104.2190(10)°, V=1228.54(7) A3, Z=4, and final R1=0.0350 for 3331 reflections with I≥2σ(I) and 186 variables. Complex 3b is isostructural with 3a [3b: monoclinic, space group P21/c, with a=6.74350(10), b=11.495, c=18.276 A, β=94.2250(10)°, V=1412.88(2) A3, Z=4, and final R1=0.0482 for 4072 reflections with I≥2σ(I) and 223 variables]. Crystals of 11 are monoclinic, space group C2/c, with a=14.5510(8), b=5.6901(3), c=14.2792(8) A, β=117.079(1)°, V=1052.67(10) A3, Z=4, and final R1=0.0263 for 1504 reflections with I≥2σ(I) and 82 variables. Crystals of 12 are triclinic [P 1 , a=9.6569(12), b=10.3194(14), c=10.367(2) A, α=81.046(11), β=82.577(12), γ=75.405(12)°, V=983.2(3) A3, Z=2, R1=0.0314, 5461 reflections I≥2σ(I), 344 variables], while 13 is crystallizing in the monoclinic space group C2/c, with a=16.6967(19), b=8.9933(10), c=20.254(2) A, β=106.962(2)°, V=2909.0(6) A3, Z=4, and final R1=0.0623 for 3419 reflections with I≥2σ(I) and 200 variables. Complexes 3a, 3b and 11 contain a monomeric [OsO2Cl2L2] unit (L=pyz, cpy, Hpz) in which the group-8 transition metal atom is octahedrally coordinated. Complexes 3a and 3b are cis-configurated, while 11 is trans-orientated in the solid-state. A coordination polymer is formed by the formation of hydrogen bridges between the hydrogen atom of the Hpz ligands (NH) with the osmium-bound oxygen atoms of individual [OsO2Cl2(Hpz)2] building blocks. In 12 four pyrazole ligands are datively-bound to a OsO2 entity, whereby the oxygen atoms occupy the axial and the Hpz ligands the equatorial positions of the OsO2(Hpz)4 octahedron. Through the formation of NH⋯ONO2⋯HN bridges between OsO2(Hpz)4 units a polymeric structure is set-up. In homobimetallic 13 two OsO2(Hpz)2 moieties are spanned by two pz− units. The NO3 − ions act, as in 12, as bridging units between the Hpz ligands of individual OsO2(Hpz)2 entities by forming NH⋯ONO2⋯HN structures. In addition, a solvent molecule MeOH is bound to an oxygen atom of a OsO2(Hpz)2 unit forming a MeOH⋯OOs building block. The synthesized osmium(VI) complexes allow systematic and comparative studies on their electrochemical behaviour, which also will be discussed in detail.

The synthesis of the heterobimetallic platinum(II)–silver(I) complex {cis-[Pt](CCPh)2}AgFBF3 (3) in which the respective transition metals are bridged by σ- and π-bound phenylacetylides, succeeds by the reaction of cis-[Pt](CCPh)2 {[Pt]=(bipy′)Pt, bipy′=4,4′-dimethyl-2,2′-bipyridine} (1) with equimolar amounts of [AgBF4] (2). The reaction chemistry towards different Lewis-bases L (L=tetrahydrofuran, NR3, PPh3) is reported. Although 3 reacts with L to give coordination adducts of general type [{cis-[Pt](CCPh)2}AgL]BF4 in which the Lewis-base L is datively bound to the silver(I) ion, such a complex could only be isolated and characterised when L resembles PPh3 (4). All other Lewis-bases L are forming reversible adducts, which are only stable, when an excess of L is used. While [{cis-[Pt](CCPh)2}Ag(PPh3)]BF4 (5) is stable in the solid-state, it appeared that in solution it rearranges to produce the mononuclear, ionic platinum(II) complex {[Pt](CCPh) (PPh3)}BF4 (6) along with [AgCCPh] (8). The result of the X-ray structure analysis of 1 and 6 is reported. Complex 1 crystallises in the monoclinic space group C2/c with following cell parameters: a=19.3538(3), b=13.5356(3), c=8.9716(2) A, β=108.540(1)°, V=2228.27(8) A3, Z=4 and δ=1.734 g mol−1. Complex 6 crystallises in the monoclinic space group P21/n with a=9.0321(1), b=22.8014(4), c=15.6304(3) A, β=100.2414(7)°, V=3167.71(9) A3, Z=4 and δ=1.739 g mol−1. In both complexes a square-planar environment around the d8-configurated platinum(II) ion is typical. Each complex features a chelate-bound bipy′ group. To reach the coordination number four, two PhCC ligands (1) or one phenylacetylide and a PPh3 group (6) are σ- or datively bound to the platinum atom.

The thallium(I) salts of tris(pyrazolyl)methanesulfonate (Tpms) and tris(3-tert-butylpyrazolyl)methanesulfonate (TpmstBu) have been used to prepare the following complexes: [(TpmstBu)ZnX] [X = Cl (1a), Br (1b), I (1c), Et (3), OAc (5a)], [(TpmstBu)NiX] [X = Cl (2a), Br (2b)], [(TpmstBu)CoCl(HpztBu)] (3), [(TpmstBu)Zn(μ-OAc)(μ-OH)Zn(TpmstBu)] (5b), [(TpmstBu)Cu(CO)] (6a), and [(Tpms)Cu(CO)] (6b). The solid-state structures of 1b, 2a, 3, and 5b have been determined by X-ray analysis. The optical spectra of 2a and 3 were investigated by means of the angular overlap model to elucidate their electronic structures in view of the underlying molecular geometries. Variable-temperature NMR and IR spectroscopic studies show that Tpms and TpmstBu can act as N,N,N and N,N,O ligands. Both coordination modes are present in solution for the zinc complexes 1a,b and the copper carbonyl complexes 6a,b. The N,N,O bonding mode is entropically favoured in solution. For the nickel complexes 2a,b, the TpmstBu ligand acts as a tripodal nitrogen ligand in the solid state and in solution. For the dinuclear zinc complex 5b, one of the TpmstBu ligands acts as an N,N,O ligand and one as an N,O ligand. Complex 5b is one of the very few structural models of the dinuclear zinc enzymes phospholipase C and phosphotriesterase. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

The novel trinuclear complexes [(Pt{C6H3(CH2NMe22,6)2})2(μ-Hbiim)2Os(O=PPh3)2](NO3)(SO3CF3)2 [C6H3(CH2NMe2-2,6)2 = pincer ligand, H2biim = 2,2′-biimidazole] and [(PdL)2(μ-biim)2Os(O=PPh3)2](NO3)3 (L = cod, 1,5-cyclooctadiene or L = en, ethylene-1,2-diamine) were prepared by the reaction of the mononuclear complex [Os(H2biim)2(O=PPh3)2](NO3)3 with [Pt{C6H3(CH2NMe2-2,6)2}](SO3CF3), or with PdL(NO3)2 (L = cod or L = en), in the presence of a base. The exchange reaction between [Os(Hbiim)2(O=PPh3)2](NO3)3 and [Me2NH2][RhCl4(NHMe2)] led to the formation of [Os(Hbiim)2(O=PPh3)2][RhCl4(NHMe2)]. The solid-state structures of [Os(Hbiim)2(O=PPh3)2][RhCl4(NHMe2)] and [(Pt{C6H3(CH2NMe2-2,6)2})2(μ-Hbiim)2Os(O=PPh3)2](NO3)(SO3CF3)2·4H2O were determined by single-crystal X-ray diffraction. The crystals of [Os(Hbiim)2(O=PPh3)2][RhCl4(NHMe2)] are triclinic with a space group P , with a = 10.4293(5), b = 10.6365(6), c = 13.0287(7) A, β = 91.6840(10), γ = 109.8540(10)°, V = 1316.14(12) A3, Z = 1. The crystals of the complex [(Pt{C6H3(CH2NMe2-2,6)2})2(μHbiim)2Os(O=PPh3)2](NO3)(SO3CF3)2·4H2O are triclinic with a space group P , with a = 12.604(3), b = 13.471(3), c = 14.347(3) A, β =77.530(5), γ = 66.613(4)°, V = 2005.6(7) A3, Z = 1. Deprotonation of 2,2′-biimidazole in the mononuclear osmium complex, followed by coordination to an additional transition metal fragment leads to a modification of the ligand field and a variation of the redox properties of the OsIII center. [{Pd(cod)}2(μ-biim)2Os(O=PPh3)2](NO3)3 shows significant catalytic activity towards hydrogenation of terminal and cyclic alkenes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

N-(2′-Hydroxy-4′-N,N-dimethylaminobenzylidene)-4-nitroaniline [HDBN] has been used as a model for investigating intra- and intermolecular D–A (donor–acceptor) interactions in various environments by means of UV/Vis spectroscopy. UV/Vis spectra of HDBN have been measured in various solvents, ethanolic solutions of different pH, adsorbed on silica, and in the solid state. A bathochromic shift of νmax is observed with increasing the dipolarity/polarizability and HBD (hydrogen bond donor) capacity of the solvent, which is described by means of a multiple LSE (linear solvation energy) relationship in terms of the empirical Kamlet-Taft solvent polarity parameters. The adsorption of HDBN on Aerosil® 300-silica particles in non-HBA (hydrogen bond acceptor) solvents is explained in the same sense. Mobile protons and sol–gel entrapping cause a hypsochromic shift due to protonation of the lone electron pair of the 4′-N,N-dimethylamino group. Hydroxide ions attack the 2′-hydroxy group which causes a bathochromic shift. A strong intramolecular hydrogen bond between the 2′-hydroxyl hydrogen and the imine nitrogen atom is present in the solid-state structure causing an unprecedented bathochromic shift.

[4-Di(2-acetoxyethyl)aminophenyl]-2-furylmethanone [Fur(OAc) 2 ], [4-di(2-hydroxyethyl)-aminophenyl]-2-furylmethanone [Fur(OH) 2 ], and their thiophene analogues, [4-di(2-acetoxy-ethyl)aminophenyl]-2-thienylmethanone [Thi(OAc) 2 ] and [4-di(2-hydroxyethyl)aminophenyl]-2-thienylmethanone [Thi(OH) 2 ], have been synthesized as model compounds for the study of molecular interactions in the solid-state and liquid environments with different polarity. The UV/Vis absorption spectra of these compounds have been studied in 30 solvents of different polarity and hydrogen bonding ability. The solvent dependent UV/Vis spectroscopic band shifts ν max are analyzed using the empirical Kamlet-Taft solvent parameters π* (dipolarity/polarizability), α (hydrogen bond donating capacity), and β (hydrogen bond accepting ability) in terms of the well-established linear solvation energy relationship (LSErs): ν max = (ν max ) 0 + sπ* + aα + bβ. The solvent independent coefficients s, a, and b and (ν max ) 0 have been determined. To evaluate the environmental effects for Fur(OH) 2 and Thi(OH) 2 , the UV/Vis spectroscopic behavior of these compounds was also investigated as pure crystal powders and as a guest in ormosil sol-gel glasses. The solid-state structures of the latter compounds were determined by single-crystal X-ray diffraction techniques. The X-ray investigations confirm the existence of qualitatively different intermolecular hydrogen bonds in Fur(OH) 2 and Thi(OH) 2 , which are additionally reflected by the UV/Vis reflectance absorption spectra and are related to the solvatochromism result.

The protolytic equilibria of copper(II), 5, 5′-dimethyl-2, 2′-bipyridine (bpy) and iminodiacetate (IDA) have been investigated by potentiometric titration between pH 2 and 8. Potentiometric titration suggests the presence of [Cu(IDA)(bpy)]0 at a fraction of 28 % of all copper species in solution at pH 8 with a stability constant logβ = 13.9. The crystal structures of [Cu(IDA)(bpy)] · 4H2O (1) and [Cu(IDA)(H2O)(phen)] · 4H2O (2) show the IDA ligand coordinated in the fac-NO+O mode. The structure of 1 features “dimeric” entities of symmetry-independent five-coordinated Cu-complexes through a long Cu···O contact, hydrogen bonding and π-stacking, including a “pyridyl—metal-chelate ring” π-contact as evidence for metalloaromaticity in aromatic α, α′-diimine-copper(II) chelates. The structure of 2 has the tetragonally six-coordinated molecular Cu-complexes arranged by hydrogen bonding and π-stacking. The crystal water in 2 forms infinite corrugated double chains composed of alternating four- and six-membered, edge-sharing rings of hydrogen-bonded water molecules. Synthese, Struktur und Verhalten in Losung von (5, 5′-Dimethyl-2, 2′-bipyridin)(IDA)kupfer(II) und Strukturvergleich mit Aqua(IDA)(1, 10-phenanthrolin)kupfer(II) (IDA = iminodiacetato) Das Protolysegleichgewicht zwischen Kupfer(II), 5, 5′-Dimethyl-2, 2′-bipyridin (bpy) und Iminodiacetat (IDA) wurde mittels potentiometrischer Titration zwischen pH 2 und 8 untersucht. Die Ergebnisse der potentiometrischen Titration deuten das Vorhandensein der Verbindung [Cu(IDA)(bpy)]0 mit einem Anteil von 28 % an allen Kupferspezies in Losung bei pH 8 mit einer Stabilitatskonstante von logβ = 13.9 an. Die Kristallstrukturen von [Cu(IDA)(bpy)]·4H2O (1) und [Cu(IDA)(H2O)(phen)]·4H2O (2) zeigen den IDA-Liganden in der fac-NO+O Koordination. Die Struktur von 1 zeigt “dimere” Einheiten aus symmetrieunabhangigen funffach-koordinierten Kupferkomplexen, zusammengehalten durch langen Cu···O-Kontakt, H-Brucke und π-Stapelung, einschlieslich eines “Pyridyl—Metall-Chelatring”-π-Kontaktes als Hinweis auf Metalloaromatizitat in aromatischen α, α′-Diimin-Kupfer(II)-Chelaten. Die Struktur von 2 weist tetragonal sechsfach-koordinierte molekulare Cu-Komplexe auf, die durch H-Brucken und π-Stapelung gepackt sind. Das Kristallwasser in 2 bildet unendliche, gewellte Doppelketten, die aus alternierenden vier- und sechsgliedrigen kantenverknupften Ringen der H-Brucken-gebundenen Wassermolekule aufgebaut sind.

The solvatochromism (νmax) of N-substituted Michler’s ketones − including 4′-[bis(2-acetoxyethyl)amino]-4-(dimethylamino)benzophenone [MK(OAc)2, 1a], 4,4′-bis(diethylamino)benzophenone [MK(NEt2)2, 1e], 4,4′-bis(4-ethoxycarbonylpiperazino)benzophenone [MK(pipOEt)2, 2a], 4,4′-bis(piperidino)benzophenone [MK(pip)2, 2b], 4,4′-bis(morpholino)benzophenone [MK(mor)2, 2c], 4,4′-bis(piperazino)benzophenone [MK(pipaz)2, 2d], 4,4′-bis[4-(2-hydroxyethyl)piperazino]benzophenone [MK(pipazOH)2, 2e] and 1,4-bis(4-benzoylphenyl)piperazine (BBP, 3) − has been studied at 298 K in various solvents with wide ranging dipolarities and hydrogen-bonding abilities. The solvatochromic properties (νmax)s = (νmax)0 + sπ* + aα + bβ have been analysed in terms of the Kamlet−Taft linear solvation energy (LSE) relationship. The effect of the solvent on the UV/Vis spectral characteristics (νmax) has been determined quantitatively for all compounds in terms of the Kamlet−Taft solvent-independent correlation coefficients s, a, and b. It was found to be mainly the dipolarity/polarizability (π*) and hydrogen bond acidity (α) of the solvent that contribute to the bathochromic UV/Vis band shift. As strongly basic sites are present as substituents at the peripheries of the molecules, protonation takes place at the secondary nitrogen atom of, for example, MK(pipaz)2 (2d) in strongly hydrogen bond-donating (HBD) solvents. This specific type of substitution therefore gives rise to an ambiguous solvatochromic property, which makes the basicity (β term) of the solvent important. The solid-state structures of 2b (C23H28N2O), 2c (C21H24N2O3), and 3 (C30H26N2O2) have been determined by single-crystal X-ray structure analysis. Compound 2b crystallizes in the trigonal space group P3121 with a = 948.11(11), b = 948.11(11), c = 1818.0(3) pm, α = β = 90, γ = 120° and Z = 3, whereas 2c crystallizes in the orthorhombic space group Pna21 with a = 1259.9(2), b = 910.16(17), c = 1586.2(3) pm, α = β = γ = 90° and Z = 4. Compound 3 crystallizes in the triclinic space group P with a = 1034.0(2), b = 1079.9(2), c = 1127.2(2) pm, α = 72.062(4), β = 73.361(4), γ = 74.549(4)° and Z = 2. The UV/Vis band shifts are comparatively discussed with regard to the LSE relationships and the results of the solid-state structure determinations. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2002)

Based on the bis(alkinyl) titanocene [Ti](CCSiMe 3 ) 2 ( 1 ) a series of mixed early–late metal complexes of the general type {[Ti](CCSiMe 3 ) 2 }ML {[Ti]=(η 5 -C 5 H 4 SiMe 3 ) 2 Ti; M=Ni, Pd; L=PPh 3 , P(OMe) 3 , P(OPh) 3 } was prepared. The solid-state structure of {[Ti](CCSiMe 3 ) 2 }Pd(PPh 3 ) ( 2 ) is reported. Complex 2 exhibits typical features of early–late heterobimetallic tweezer complexes: (i) a pseudo-tetrahedrally coordinated Ti(IV) centre; (ii) a trigonal-planar coordination sphere around the Pd(0) centre, comprised of the two η 2 -coordinated Me 3 SiCC entities and the datively-bound PPh 3 ligand; (iii) a lengthening of the CC triple bonds upon their η 2 -coordination to Pd(0); and (iv) a trans -deformation of the TiCCSiMe 3 units due to the tweezer effect. Cyclic voltammetric studies on 2 and {[Ti](CCSiMe 3 ) 2 }NiL [ 3 , L=CO; 4a , L=P(OCH 3 ) 3 ] reveal an electron donating character of the coordinated M(0) centres, which is demonstrated by the shift of the Ti(IV)/Ti(III) reduction to a more negative potential. This reductive process also exhibits a dependence on the π-acidity of the respective Lewis-base L.

Die Reaktion von [P(C6H4CH2NMe2-2)3]AgX (1a, X = OTf; 1b, X = OClO3) mit aquimolaren Mengen an LcapL (2a, LcapL = 2, 2′-Bipyridin, bipy; 2b, LcapL = 4, 4′-Dimethyl-2, 2′-bipyridin, bipy′; 2c, LcapL = 1, 10-Phenanthrolin, phen) fuhrt zu den kationischen Komplexen {[P(C6H4CH2NMe2-2)3]Ag(LcapL)}+X— (LcapL = bipy: 3a, X = OTf; 3b, X = ClO4; LcapL = bipy′: 3c, X = OTf; 3d, X = ClO4; LcapL = phen: 3e, X = OTf; 3f, X = ClO4), in denen die Bausteine LcapL und P(C6H4CH2NMe2-2)3 als zweizah nige Chelatliganden an das Silberatom koordinativ gebunden sind. Laut spektroskopischen Befunden zeigt die Phosphangruppe P(C6H4CH2NMe2-2)3 in Losung dynamisches Verhalten, wobei auf der NMR-Zeitskala ein schneller Austausch der Me2NCH2-Seitenarme stattfindet. Wahrend 3e im Festkorper bestandig ist, beobachtet man fur Losungen von 3e, dass diese sich beim Erwarmen oder unter Einwirkung von Licht zersetzen. Unter Abscheidung von kolloidalem Silber last sich nach entsprechender Aufarbeitung neben dem Phosphan P(C6H4CH2NMe2-2)3 (5) der Komplex [Ag(phen)2]OTf (4) isolieren. Die Kristallstrukturen der neutralen bzw. kationischen Komplexe 1a und 4 werden beschrieben. Einkerniges 1a kristallisiert in der monoklinen Raumgruppe P21/c mit den Zellparametern a = 16.7763(2), b = 14.7892(2), c = 25.44130(10)A, β = 106.1260(10), V = 6063.83(11)A3, Z = 4 mit 8132 beobachteten unabhangigen Reflexen (R1 = 0.0712), wahrend 4 in der monoklinen Raumgruppe C2/c mit den Zellparametern a = 26.749(3), b = 7.1550(10), c = 26.077(3)A, β = 113.503(2), V = 4576.8(10)A3, Z = 4 mit 6209 beobachteten unabhangigen Reflexen (R1 = 0.0481) kristallisiert. Die Elementarzelle von 1a enthalt zwei unabhangige Molekule. In beiden Molekulen weist das Silberatom eine verzerrt tetraedrische Umgebung auf und es liegt eine wannenformige Konformation fur die sechsgliedrigen AgPNCH2C2/Phenyl-Ringe vor. In 4 hat das Silberatom, wie in 1a, die Koordinationszahl 4. Die beiden phen-Liganden sind um 40.63° zueinander verdreht. Der OTf-Rest liegt als nicht-koordinierendes Anion vor.

The chlorodisilanes SiClMe2SiClMe2 (1), SiCl2MeSiCl2Me (2), SiCl3SiCl3 (3) and a 9:1 mixture of 2 and SiCl3SiCl2Me (4) were reacted with the electron-rich alkene tetrakis-(dimethylamino)-ethylene (TDAE) in n-hexane as well as in polar solvents. While 1 gave no reaction at all, 3 underwent a disproportionation reaction into SiCl4 and Si(SiCl3)4. Also 2 and mixtures of 2 and 4 were disproportionated into MeSiCl3 (2a) and methylchlorooligosilanes. Additionally a crystalline mixture of Si3Me3Cl6·TDAE (5a) plus Si3Me2Cl7·TDAE (5b) was obtained by reaction of a 9:1 mixture of 2 and 4 with TDAE in n-hexane as well as in 1,2-dimethoxyethane. The reaction of 2 with TDAE in acetonitrile (MeCN) led to a crystalline precipitation of [TDAE]Cl2·MeCN (6·MeCN) in addition to MeSiCl3 and methylchlorooligosilanes. The structures of 5b and 6·MeCN were determined by X-ray crystallography beside their NMR and IR spectroscopic characterization. Compound 5b crystallizes in the monoclinic space group P2/c (Z=4), 6·MeCN in the orthorhombic space group Pna21 (Z=4). The structure of 5b reveals a [TDAE] + radical cation and a 1,2-Me2Si3Cl7− anion with a pentacoordinated central silicon atom.

The trimeric diphenyltin chalcogenides (Ph 2 SnE) 3 (E=S ( 1 ), Se ( 2 ), Te( 3 )) have been synthesized by reaction of Ph 2 SnCl 2 with Li 2 E and characterized by multinuclear NMR spectroscopy ( 1 H, 13 C, 119 Sn, 77 Se and 125 Te) as well as crystal structure analyses. The three compounds crystallize in the monoclinic space group P 2 1 / n and show central six-membered rings Sn 3 E 3 in twisted boat conformations. For 1 density functional theory (DFT) calculations at the B3LYP/6-31G* level of theory have revealed the twisted boat conformation as the global minimum. Additionally a boat conformation (+3.4 kJ mol −1 ) and a chair conformation (+7.9 kJ mol −1 ) have been calculated. The mutual repulsion of the phenyl rings in the chair conformation is also evident from the increased bond angles of the Sn 3 S 3 ring in 1 .

The reactions of 1:1 mixtures of the trisilylmethane HC(SiMe2Cl)3 (1b) and organo Group 14 trichlorides (RMCl3, R=Me, Ph, vinyl (Vi); M=Si, Ge, Sn) with Li2E (E=S, Se) in THF yielded the new bicyclo[2.2.2]octanes HC(SiMe2E)3MR (2a–6b). The products were identified by GC–MS and multinuclear NMR spectroscopy. Trends of the NMR data are discussed. The molecular structures of HC(SiMe2S)3SiMe (2a), HC(SiMe2S)3SiPh (3a), HC(SiMe2Se)3SiVi (4b) and HC(SiMe2Se)3GeMe (5b) are reported.

The photolytic CO-substitution reaction of the organoiron thiocarboxylate complexes CpFe(CO)2SCOR (R=CH3, 2-CH3C6H4, 2-NO2C6H4, 4-NO2C6H4, 3,5-(NO2)2C6H3) with diphosphines (Ph2P(CH2)nPPh2) [n=1 (dppm), n=2 (dppe), n=3 (dpppr), n=4 (dppb), n=5 (dppp), n=6 (dpph)] at room temperature using 1:2 (metal–ligand) molar ratio afforded exclusively the disubstituted complexes CpFe(Ph2P(CH2)nPPh2)SCOR when n=1, 2 and 3 and the monosubstituted analogs CpFe(CO)(Ph2P(CH2)nPPh2)SCOR when n=4, 5 and 6. This reaction was found to be strongly influenced by the backbone length of the diphosphine ligand, the nature of the R group of the thiocarboxylate moiety and the metal–ligand molar ratios. The crystal structure of CpFe(dppm)SCO(3,5-(NO2)2C6H3) was determined.

The reaction of a 1:1 mixture of Ph2PbCl2 and ClSiMe2–SiMe2Cl with H2S/NEt3 yielded the mixed silicon–lead sulfide Me4Si2(S)2PbPh2 (1a), a bicyclic silicon lead sulfide, Ph2Pb(S)2Si2Me2(S)2PbPh2 (1b) was obtained by similar treatment of a 2:1 mixture of Ph2PbCl2 and Cl2SiMe–SiMeCl2. The corresponding selenium compounds (2a–b) were obtained by reactions of mixtures of Ph2PbCl2 and methylchlorodisilanes with Li2Se in THF. All products were characterized by multinuclear (1H, 13C, 29Si, 77Se and 207Pb) NMR spectroscopy. The molecular structure of 1a is reported revealing a central five membered ring Si2S2Pb in envelope conformation with one sulfur atom (S1) above the plane defined by the atoms Pb1S2Si2Si1. For comparison, the tin compounds Me4Si2(Se)2SnPh2 (4a), and Ph2Sn(Se)2Si2Me2(Se)2SnPh2 (4b) have also been prepared essentially applying the same procedure as for compounds 2a–b. A plot of δ (207Pb) of 1a–2b versus δ (119Sn) of the corresponding tin compounds 3a–4b exhibits a linear correlation with a slope of 4.11 (±0.17). Attempts to build related cycles containing a Group 15 element led to the isolation of the antimony compounds Me4Si2(E)2SbPh (5a: E=S, 5b: E=Se) starting from ClSiMe2–SiMe2Cl, PhSbCl2 and either H2S/NEt3 or Li2Se.

Treatment of [Ti](Cl)(CCSiMe3) (1) {[Ti]=(η5-C5H5)2Ti} with Ni(CO)4 (2) in a 1:1 molar ratio produces the heterobimetallic early–late transition metal complex {[Ti](Cl)(CCSiMe3)}Ni(CO) (3), which features a low-valent Ni(CO) entity stabilized by a datively bonded Cl and a η2-coordinated Me3SiCC ligand. As side-products [Ti]Cl2 (8) and {[Ti](CCSiMe3)2}Ni(CO) (5) are formed. The latter complex can also be synthesized by the reaction of [Ti](CCSiMe3)2 (4) with equimolar amounts of 2. If 3 is reacted with stoichiometric amounts of P(OR)3 (6a, R=C6H5; 6b, R=C6H4CH3-2; 6c, R=C6H4tBu-2) the bis(alkynyl) titanocene 4, (CO)2Ni[P(OR)3]2 (7a, R=C6H5; 7b, R=C6H4CH3-2; 7c, R=C6H4tBu-2), complex 8, {[Ti](μ,η1:η2-CCSiMe3)}2 (9) along with Me3SiCCCCSiMe3 (10) is produced. A possible mechanism for the formation of these species is presented. The solid-state structure of 7b is reported. Complex 7b crystallizes in the tetragonalic space group P-421c with the following parameters: a=14.852(2), b=14.852(2), c=19.410(4) A, V=4281.5(12) A3, Z=4 and ρ=1.271 g cm−3. Mononuclear 7b features a Ni(0) centre in a pseudo-tetrahedral environment, caused by the CO and P(OC6H4CH3-2)3 ligands.

The title compounds 3-5 are accessible by treatment of P(C6H4CH2NMe2)3(1) with CuX (2a: X = Cl, 2b: X = Br, 2c: X = I) in the ratio of 1:1 or 1:2 in very good yields. Reaction of 1 with equimolar amounts of 2a affords the copper(I) chloride [P(C6H4CH2NMe2)3]CuCl (3). With a further equivalent of 2a homobimetallic [P(C6H4CH2NMe2)3]Cu2Cl2 (4) is formed, which also can be synthesized by the reaction of 1 with two equivalents of 2a. Complex 3 reacts with CuX (X = Br, I)to afford [P(C6H4CH2NMe2)3]Cu2ClX (5a: X = Br; 5b: X = I) in which mixed halides are present. The newly synthesized complexes 3-5 were characterized by elemental analyses, by their IR-, 1H-, 13C{1H}- and 31P{1H}-NMR spectra as well as by mass spectrometrical studies. The solid-state structures of complexes 3 and 4 are reported. Mononuclear 3 crystallizes in the monoclinic space group P21/c with the cell parameters a = 14.285(2), b = 10.853(2), c = 17.425(2) A , β = 103.310(10)?, V = 2628.9(7) A 3 and Z = 4 with 4053 observed unique reflections; R1 = 0.0314. The crystal structure of 3 consists of monomeric molecules with planar coordinated copper(I) centres (CuClNP). Homobimetallic 4 crystallizes in the monoclinic space group P21/n with a = 23.905(4), b = 10.874(3), c = 25.314(5), β = 99.130(10)?, V = 6497(2) /Aring; 3 and Z = 4 with 9021 observed unique reflections; R1 = 0.0480. In 4 one of two copper(I) centres possesses a distorted trigonal-pyramidal environment, while the other one is almost square-pyramidal coordinated. The Cu2Cl2 segment resembles to a building block which is set up by a contact ion pair consisting of Cu+ and [CuCl2]- , respectively.

The crystal structures of inclusion compounds of 3,3′-bis(9-hydroxy-9-fluorenyl)-2,2′-binaphthyl host (1) and its chloro (2) or bromo (3) derivatives substituted in 2,7-positions of the fluorene units with acetone guests (1A–3A) were determined by X-ray studies as well as by 1H-CRAMPS solid-state NMR. Using this NMR technique allows identification of differently bound guest molecules due to their different chemical shifts caused by the influence of the ring current effects of the host aryl units.

The reaction of [Ti](CCPh)2 (1) {[Ti]=(η5-C5H4SiMe3)2Ti} with equimolar amounts of CuBr, Ni(PPh3)3 or Pd(PPh3)4 produces the heterobimetallic early–late transition metal complexes of general type {[Ti](CCPh)2}MX [2: MX=CuBr, 3: MX=Ni(PPh3), 4: MX=Pd(PPh3)} in which the respective transition metal atoms are linked by σ,π-bound alkynyl ligands. The solid-state structure of 1 and 4 is reported. In heterobimetallic 4 the Pd(0) centre possesses a trigonal–planar environment caused by the two η2-coordinated Me3SiCC ligands and the datively bonded PPh3 group. The PPh3 moiety is thereby located out of the best Ti(CCSi)2Pd plane. Comparative cyclic voltammetric studies on complexes 1–4 as well as {[Ti](CCPh)2}Ni(CO), for comparison, are presented. These studies reveal a strong influence of the η2-coordinated low-valent transition metal complex fragments MX on the reduction behaviour of the Ti(IV) centre.

The reactions of 1:1 mixtures of the isotetrasilane MeSi(SiMe2Cl)3 and organo group 14 trichlorides RMCl3 (R = Me, Ph; M = Si, Ge, Sn) with Li2E (E = S, Se, Te) in THF yielded the new bicyclo[2.2.2...

Treatment of P(C6H4CH2NMe2-2)3 (1) with 2 equiv. of CuX (2a X=Cl, 2b X=Br) produces the novel dicopper complexes [P(C6H4CH2NMe2-2)3]Cu2X2 (3a X=Cl, 3b X=Br) in high yields. The X-ray structure of 3b was determined. Crystals of 3b are orthorhombic, space group Pna21, with a=19.280(4) A, b=15.717(3) A, c=11.201(2) A, V=3394(1) A3, Z=4, and final R1=0.0573 [I≥2σ(I)] for 2301 reflections used (1621 reflection with I≥2σ(I)) and 340 variables. The structure of 3b consists of two copper(I) centers of which one copper atom possesses a heavily distorted trigonal-pyramidal environment, while the other one is almost square-pyramidal coordinated; the Cu2Br2 segment gives rise to a situation, which may be considered as a contact ion pair between Cu+ and CuBr2 −.

Treatment of OsO4 (1) with 2,2′-biimidazole (H2biim) (2) in a methanol/acetone mixture, and in the presence of nitric acid produces the novel dioxoosmium(VI) complex [OsO2(H2biim)2](NO3)2·CH3OH (3). Addition of 2 equiv. of PPh3 (4) and 1 equiv. of nitric acid to 3 affords mononuclear [Os(H2biim)2(O=PPh3)2](NO3)3 (5) by a redox reaction which involves the transfer of oxygen from osmium to PPh3. The X-ray crystal structure of 5 reveals an octahedral coordination sphere around the osmium(III) centre. This occurs as a result of the two H2biim chelating ligands in the equatorial positions and two datively bonded phosphane oxide groups O=PPh3 in the axial positions. Hydrogen bonds are responsible for the formation of a polymeric structure in the solid state. The latter complex reacts with KOH to form monocationic [Os(Hbiim)2(O=PPh3)2]NO3 (6).

The cyclotetrasiloxane [(Me)(C6H4CH2NMe2-2)SiO]4 (2) can be synthesized by hydrolysis of the pentacoordinated silicon compounds (C6H4CH2NMe2-2)MeSiCl2 (1 )o r (C 6H4CH2NMe2-2)MeSi(OR)2 (3a ,R = CH2CHCH2; 3b ,R = CH2CCH) in quantitative yield. The solid-state structure of 2 is reported. Compound 2 crystallizes in the triclinic space group P-1 with the following cell parameters: a=9.575(2), b=15.018(3), c = 16.021(4) A ; = 94.72(12), = 90.96(2), = 103.75(2)°; V = 2228.5(9) A 3 and Z=2. Due to sterical hindrance the silicon atoms in 2 are tetra-coordinated, which differs from the starting materials 1, 3a and 3b, where hypervalent silicon centers exist. © 2001 Elsevier Science B.V. All rights reserved. Zusammenfassung

Reactions of mixtures of Cl2MeSiSiMeCl2 (1) and Me2MCl2 (M=Si, Ge, Sn) with either H2S/NEt3 or Li2E (E=Se, Te) yielded the bicyclo[3.3.0]octanes Me2M(E)2Si2Me2(E)2MMe2. A carbon containing analog, (CH2)5C(S)2Si2Me2(S)2C(CH2)5, was prepared from 1 and (CH2)5C(SH)2. Crystal structures of three of these compounds were determined and the observed conformations of the bicyclo[3.3.0]octane skeletons compared with results of density functional theory calculations. Another class of silchalcogenides featuring a bicyclo[3.3.0]octane skeleton, E(Me2Si)2Si2Me2(SiMe2)2E, was formed from the doubly branched hexasilane (ClMe2Si)2Si2Me2(SiMe2Cl)2 and H2S/NEt3 or Li2E. All products were characterized by multinuclear NMR (1H, 13C, 29Si, 77Se, 119Sn, and 125Te).

Die Umsetzung des tetrapodalen Phosphans P(C6H4CH2NMe2-2)3 (1) mit aquivalenten Mengen der Silber(I)-Halogenide AgX (2 a: X = Cl, 2 b: X = Br) in Tetrahydrofuran bei 25 °C fuhrt zu den monomeren Silber(I)-Komplexen [P(C6H4CH2NMe2-2)3]AgX mit planarer Umgebung an den Ag-Atomen (3 a: X = Cl, 3 b: X = Br) in sehr guter Ausbeute. Von Komplex 3 b wurde eine Einkristall-Rontgenstrukturanalyse angefertigt. Einkerniges 3 b kristallisiert in der monoklinen Raumgruppe P21/c mit den Zellparametern a = 14.504(6), b = 11.034(3), c = 17.604(5) A, β = 102.86(4)°; V = 2746.6(16) A3; Z = 4; 2953 beobachtete unabhangige Reflexe, R1 = 0.0805. Aufgebaut ist 3 b aus monomeren Untereinheiten mit planarer, T-formiger Anordnung vorgegeben durch die Atome Ag1, N1, P1 sowie Br1, wobei das Segment P1–Ag1–Br1 nahezu linear angeordnet ist. Synthesis of Monomeric T-Shaped Silver(I) Halide Complexes – Crystal Structure Analysis of [P(C6H4CH2NMe2-2)3]AgBr Treatment of the tetrapodal phosphane P(C6H4CH2NMe2-2)3 (1) with equimolar amounts of the silver(I) halides AgX (2 a: X = Cl, 2 b: X = Br) produces in tetrahydrofuran at 25 °C the monomeric silver(I) complexes [P(C6H4CH2NMe2-2)3]AgX with planar coordination at the Ag atoms (3 a: X = Cl, 3 b: X = Br) in excellent yields. From complex 3 b a single X-ray crystal structure analysis was carried out. Mononuclear 3 b crystallizes in the monoclinic space group P21/c with the cell parameters a = 14.504(6), b = 11.034(3), c = 17.604(5) A, β = 102.86(4)°; V = 2746.6(16) A3; Z = 4; 2953 observed unique reflections, R1 = 0.0805. Complex 3 b consists of monomeric sub-units with a planar T-shaped arrangement formed by the atoms Ag1, N1, P1 as well as Br1, whereby the P1–Ag1–Br1 array is almost linear orientated.

Thallium(I) tris(pyrazol-1-yl)methanesulfonate (TlTpms) has been prepared as a new versatile precursor for Tpms complexes. TlTpms readily reacts with the rhodium(I) complexes [Rh(LL)Cl]2 [LL = (CO)2, cod, nbd] to give the corresponding TpmsRh(LL) complexes [LL = (CO)2 (2a), cod (3), and nbd (4)]. In solution, 2a reversibly forms the binuclear complex TpmsRh(µ-CO)3RhTpms (2b). 3 and 4 react with CO to form 2a. TpmsRh(CO)(PR3) complexes [PR3 = PPh3 (5a), PMe3 (5b), PCy3 (5d), P(Ph)2(PhSO3K) (5e)] have been obtained by reaction of 2a with the corresponding phosphanes. The solid-state structures of 2a, 3, 4, and 5a have been determined by X-ray analysis. 2a, 3, and 5a have square-planar geometries with the Tpms ligand coordinating in a κ2 mode. The non-coordinating pyrazole ring faces either away from (structure 2a) or towards the rhodium atom (structures 3 and 5a). 4 has a trigonal-bipyramidal coordination geometry with a genuine κ3-bonded Tpms ligand. The non-rigid behaviour of the (Tpms)rhodium complexes has been followed by variable-temperature NMR studies. IR studies on 2a and 5a−e show that Tpms is a weakly donating ligand, comparable to the Tp and Tp ligands. Compound 5e is soluble and stable in dilute acids, showing that Tpms, unlike the Tp ligand, is hydrolytically stable.

The reactions of Me 2 MCl 2 (M=Si, Ge, Sn) with either H 2 S/NEt 3 or Li 2 E (E=Se, Te) yielded the six-membered-ring compounds (Me 2 ME) 3 . Similarly the treatment of ClMe 2 SiSiMe 2 Cl ( 1 ) with H 2 S/NEt 3 or Li 2 E resulted in the formation of E(Si 2 Me 4 ) 2 E. Mixed species E(Si 2 Me 4 ) 2 E′ could be obtained by reaction with mixtures of Li 2 E and Li 2 E′ or in the presence of traces of moisture (E′=O). Reactions of 1:1 mixtures of Me 2 MCl 2 and 1 with Li 2 E resulted in exclusive or at least preferred formation of five-membered rings Me 4 Si 2 (E) 2 MMe 2 . A carbon analogue, Me 4 Si 2 (S) 2 C(CH 2 ) 5 , was obtained from 1 and (HS) 2 C(CH 2 ) 5 . Boron could also be introduced in these ring systems, starting from PhBCl 2 and 1 the compounds PhB(E) 2 Si 2 Me 4 (E=S, Se) could be synthesized. Mixtures of 1 and Cl 2 MeSiSiMeCl 2 yielded, on treatment either with H 2 S/NEt 3 or Li 2 E (E=Se, Te), the bis(cyclopentyl) compounds [Me 4 Si 2 (E) 2 SiMe] 2 . All products have been characterized by multinuclear NMR ( 1 H, 11 B, 13 C, 29 Si, 77 Se, 119 Sn, 125 Te) measurements including coupling constants. Trends of chemical shifts and coupling constants are discussed. The crystal structures of E(Si 2 Me 4 ) 2 E (E=S, Se) and [Me 4 Si 2 (S) 2 SiMe] 2 are reported.