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2,2′‐Bipyrazine (2,2′‐bpz) reacts with cis‐(NH3)2PtIIin water to give a variety of products, several of which were isolated and characterized by X‐ray analysis: cis‐[Pt(NH3)2(2,2′‐bpz‐N4)2](NO3)2⋅3 H2O (1), [{cis‐Pt(NH3)2(2,2′‐bpz‐N4,N4′)}3](PF6)5NO3⋅7 H2O (2 a), [{cis‐Pt(NH3)2(2,2′‐bpz‐N4,N4′)}3](BF4)2(SiF6)2⋅15 H2O (2 b), and [{cis‐Pt(NH3)2(2,2′‐bpz‐N4,N4′)}4](SO4)4⋅22 H2O (3). In 1, 2 b, and 3the 2,2′‐bpz ligands adopt approximately C2hsymmetries, hence the two pyrazine halves are in transorientation, whereas in 2 aall three 2,2′‐bpz bridges are approximately C2vsymmetric, with the pyrazine halves cisto each other. The topologies of the two triangular complexes 2 aand 2 bare consequently distinctly different, but nevertheless both cations act as hosts for anions. In 2 aa PF6−and a NO3−anion are associated simultaneously with the +6 cation, whereas in 2 bit is a BF4−anion and a water molecule, which are trapped in its cavity. There is no anion inclusion in case of the metallasquare 3. In principle, 3can exist in a large number of stereoisomers, depending on the rotational states of the bridging 2,2′‐bpz ligands. Isolation of a single rotamer form of 3with C2hsymmetric 2,2′‐bpz ligands and an overall mesoform is proposed to be a consequence of a highly efficient self‐assembly process that starts from the precursor 1and reaction with two cis‐(NH3)2PtIIunits. This process leads to the isolated rotamer of 3regardless of whether two cations 1in head–head form react with two cis‐(NH3)2PtII, or whether the Δ enantiomer of the chiral head–tail form of 1combines with its Λ enantiomer through two cis‐(NH3)2PtIIentities.

Große Vielfalt: Eine Synthesestrategie mit Reaktionskaskaden oder Dominoreaktionen ergab fokussierte Verbindungsbibliotheken mit komplexen und diversen Molekülstrukturen. Ausgehend von einem gemeinsamen mehrfach funktionalisierten Substrat führten Reaktionskaskaden zu vielfältigen – naturstoffähnlichen ebenso wie grundlegend neuartigen – Molekülgerüsten (siehe Bild).

Touch 'n' transform: A synthetic strategy based on cascade or domino reaction sequences enabled the simultaneous incorporation of skeletal diversity and molecular complexity in focused compound collections. Thus, the treatment of a common multifunctionalized substrate with various cascade‐triggering molecules (see picture) generated a wide range of both natural product related and unprecedented molecular frameworks.

The synthesis of the intramolecularly coordinated pentacarbonyltungsten–organostannylene complexes {2,6‐(Me2NCH2)2C6H3}Sn(H)W(CO)5(2) and [{2,6‐(Me2NCH2)2C6H3}Sn(μ‐OH)W(CO)5]2(3) and the solid‐state molecular structure of 3, as determined by single‐crystal X‐ray diffraction analysis, are reported. Compound 3is characterized by hydroxido bridges [Sn–O 2.068(5), 2.231(5) Å], an intramolecular N→Sn coordination bond [2.501(7) Å] and an intramolecular O–H···N hydrogen bond [O···N 2.715(8) Å].

The syntheses of the arylphosphonic esters 3‐Br‐5‐tBu‐1‐{P(O)(OiPr)2}C6H3(1), 5‐tBu‐1,3‐{P(O)(OiPr)2}2C6H3(2), of the heteroleptic intramolecularly coordinated organostannylenes [4‐tBu‐2,6‐{P(O)(OiPr)2}2C6H2]SnX(3, X= Cl; 4, X= Br; 5, X= I; 6, X= SPh), the organoplumbylene [4‐tBu‐2,6‐{P(O)(OiPr)2}2C6H2]PbCl (7), and the transition metal complex [4‐tBu‐2,6‐{P(O)(OiPr)2}2C6H2]Sn(Cl)Cr(CO)5(8) are reported. The compounds were characterized by 1H, 13C, 31P, 31P MAS (3), 119Sn, and 119Sn MAS (3) NMR spectroscopy, electrospray ionization mass spectrometry (3), Mössbauer spectroscopy (3–5, 8) and single‐crystal X‐ray diffraction analyses (2, 3–5, 6–8). In contrast to its ethoxy‐substituted analogue [4‐tBu‐2,6‐{P(O)(OEt)2}2C6H2]SnCl, compound 3, like the thiophenolate derivative 6, is monomeric in solution as well as in the solid state. This difference is also manifested by the Mössbauer as well as solid state NMR spectroscopic data. On the other hand, the corresponding organoplumbylene 7shows a similar chlorido‐bridged polymeric structure as its ethoxy‐substituted analogue. Variable‐temperature and concentration‐dependent 1H and 31P NMR spectra reveal, on the respective time scales, the tin atom in compound 3to be configurationally unstable and those in compounds 6and 8to be configurationally stable. DFT calculations support a chlorido‐bridged dimer to account for the configurational instability in compound 3. Surprisingly and in contrast to compounds 3and 6, the organobromido‐ and organoiodidostannylenes 4and 5, respectively, show intermolecular Sn···Sn distances of 3.6809(4) and 3.5953(4) Å being shorter than twice the van der Waals radius of tin (2.20 Å). Quantum chemical calculations were performed on monomeric and dimeric model compounds, which revealed a weak Sn···Sn bonding interaction for dimer 3(16 kJ·mol–1) as well as for dimer 5(20 kJ·mol–1) whereas the hypothetical model compound p‐tBuC6H4SnI showed an iodido‐bridged dimer rather than a Sn···Sn bonding interaction.

The reaction of silver perchlorate with [PhI2SnCH2([16]crown‐5)] (1) and [I3SnCH2([16]crown‐5)] (2) gave the organotin(IV)‐substituted crown ether complexes [PhSnCH2([16]crown‐5)][ClO4]2(3) and [HOSnCH2([16]crown‐5)][Y]2(4: Y=ClO4, 5: Y=CF3SO3), respectively. All compounds have been isolated as air‐stable materials and characterised by 1H, 13C, 119Sn and 119Sn MAS (5) NMR spectroscopy, ESIMS spectrometry, elemental analysis and by single‐crystal X‐ray diffraction analysis. The molecular structures of 3–5show that the tin(IV) cation fits perfectly into the crown ether cavity and is coordinated by the five oxygen atoms of the ring to give a pentagonal bipyramidal configuration about the central metal cation. Notably, compounds 4and 5contain the first monomeric monoorganotin dication. Moreover, there are 3J(1H,119Sn) coupling constants to the CH2CHproton of 377 (3) and 470 Hz (4, 5) that are, to the best of our knowledge, the biggest such couplings ever reported.

A general onepot synthesis of new substituted heteroscorpionate ligands is presented. These mixedfunctionality ligands were obtained in a catalyzed Peterson rearrangement starting from the substituted pyrazole, thionyl chloride, and an aldehyde. Thus, the synthesis of polyfunctional tridentate ligands is enabled, and they contain, besides the two pyrazole groups, other functionalities relevant for coordination chemistry. Additionally, the steric hindrance is easily defined in the ligands by the substitution of the pyrazole rings. By combination of the versatility in donor function and steric demand, a systematic tuning of the properties of the bispyrazolylmethane ligands is possible. The synthesis and full characterization of 11 bispyrazolylmethane ligands are reported. Two of these were structurally characterized as well.

The molecular structures of the intramolecularly coordinated tungstenpentacarbonyl organostannylene complexes 2,6Me2NCH22C6H3ClSnWCO5and [2,6Me2NCH22C6H3H2OSnWCO5]+CB11H12–are reported. The latter compound is an aqua complex in which the water molecule replaces one of the two N→Sn coordination sites. The coordination of the water molecule is accompanied by proton transfer to the nitrogen atom. DFT calculations reveal this to be the thermodynamically moststable structure.

UV‐irradiation of the diorganosilane [4‐tBu‐2,6‐{P(O)(OiPr)2}2C6H2]SiH2Ph in the presence of W(CO)6provided a mixture consisting of the diorganosilylene tungsten pentacarbonyl complex [4‐tBu‐2,6‐{P(O)(OiPr)2}2C6H2](Ph)SiW(CO)5(2), the organosilylium salt [4‐tBu‐2,6‐{P(O)(OiPr)2}2C6H2Si(H)Ph]+[{(CO)5W}2H]–(3), and an unidentified species. UV‐irradiation of the triorganosilane [4‐tBu‐2,6‐{P(O)(OiPr)2}2C6H2]SiHPh2in presence of W(CO)6provided the organosilylium salt [4‐tBu‐2,6‐{P(O)(OiPr)2}2C6H2SiPh2]+[{(CO)5W}2H]–(6) whereas, under the same conditions, no reaction was observed between the tetraorganosilane [4‐tBu‐2,6‐{P(O)(OiPr)2}2C6H2]SiPh3and W(CO)6. The reaction of compound 2with Ph3C+PF6–gave the fluorine‐substituted silylene complex [4‐tBu‐2,6‐{P(O)(OiPr)2}2C6H2](F)SiW(CO)5(4) whereas the reactions of 3with Ph4PBr and 5with water gave the benzoxasilaphospholes 3a, 3b, and 7, respectively. The compounds 2and 6were isolated and characterized by 1H, 13C, 29Si, 31P NMR, and IR spectroscopy, electrospray ionization mass spectrometry, and in case of 2also by single‐crystal X‐ray diffraction analysis. The compounds 3, 3a, 3b, 4, and 7were not isolated but identified unambiguously by NMR spectroscopy and electrospray ionization mass spectrometry.

The synthesis of the intramolecularly coordinated organostannylene ruthenium complex [4‐tBu‐2,6‐{P(O)(O‐iPr)2}2‐C6H2]Sn(Cl)Ru(C6H6)Cl2, 1, is reported. It is characterized by elemental analysis, 1H, 13C, 31P, 119Sn NMR spectroscopy, and, as its toluene solvate 1·C7H8, by single‐crystal X‐ray diffraction analysis. In compound 1·C7H8the tin atom is five‐coordinate and shows a strongly distorted trigonal‐bipyramidal configuration. The intramolecular O–Sn distances are 2.291(3) and 2.394(3) Å. The Sn–Ru distance is 2.5856 Å.

Broad spectrum: Novel para‐functionalized aryl‐di‐tert‐butylfluorosilanes, p‐(tBu2FSi)C6H4X (X=functional group), have been made available and broaden the spectrum of silicon‐based 18F acceptors (SiFAs) for potential PET applications. For example, the [18F]maleimido derivative 1has been employed for the synthesis of [18F]1‐ labeled rat serum albumin (RSA), the applicability of which for PET has been verified by in vivo experiments.

Single crystal X‐ray diffraction analyses of LSn(OCH2CH2)2NR [1, R = Me, L = lone pair; 2, R = Me, L = W(CO)5; 3, R = t‐Bu, L = W(CO)5] reveal these compounds to be dimeric and cis‐configurated. The dimerization is realized by intramolecular O→Sn interactions to give four‐membered Sn2O2‐rings. In addition, there are intramolecular N→Sn interactions ranging in between 2.356(5) (2) and 2.549(4) Å (3).

Von Naturstoffen abgeschaut: Elektronenarme Oxadiene und Acetylencarboxylate reagieren in Gegenwart eines Organokatalysators effizient und stereoselektiv zu tricyclischen Benzopyronen nach natürlichem Vorbild (bis 99 % Ausbeute und 87 % ee; siehe Schema). Im Zuge dieser leicht ausführbaren asymmetrischen Anellierung werden die Acetylencarboxylate in Zwitterionen überführt.

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Single‐crystal X‐ray diffraction analysis of [2,6‐(Me2NCH2)2C6H3]2SnF2reveals that only one of the two dimethylaminomethyl groups of each pincer‐type ligands [2,6‐(CH2NMe2)2C6H3]−is coordinated to the tin atom at Sn‐N distances of 2.576(2) and 2.470(2) Å, inducing chirality of the latter. The tin atom exhibits a distorted octahedral trans(C,C)cis(N,N)cis(F,F) configuration. Extensive intra‐ and intermolecular C‐H···F hydrogen bonding is observed with the latter giving rise to formation of polymeric chains.

A variety of benzyllanthanide complexes have been prepared by the metathesis reaction of benzylpotassium precursors with lanthanide halides. Syntheses and crystal structures for the following complexes are described: [2-Me2N-a-Me3Si-benzyl]2Eu(II)·(THF)2(1-Eu), (2-Me2Nbenzyl) 3Ln(III) (2-Ln with Ln = Nd, Sm, Dy, Ho, Yb), (4-R-C6H4CH2)3Ln·(THF)3(3-Y: Ln = Y, R = H; 3-La: Ln = La, R = tBu). Complexes of types 1 and 2 are thermally robust on account of a stabilization by a benzylic Me3Si substituent and/or intramolecular coordination of the Me2N substituent. Comparison of the crystal structures of these new series of lanthanide complexes shows several similarities and trends. In addition, comparisons with alkali metal and alkaline earth metal benzyl complexes are made.

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The allenic bipyridines 3, which represent a new class of axially chiral ligands for transition metal catalysis, were synthesized and their complexation properties were studied. The synthesis was achieved by copper-mediated or palladium-catalyzed SN2′-substitution of the tertiary propargyl acetates 2. The allenic bipyridines form 1:1 complexes with Cu+ and Ag+ ions that were characterized by electrospray mass spectrometry and temperature-dependent NMR spectroscopy. In the case of the C2-symmetrical allene 3b, a crystalline silver complex was isolated that exists as a 2:2-(L2M2) complex in the solid state.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

The synthesis of the crown‐ether‐substituted bis(organostannyl)methanes Ph3SnCH2Sn(Ph2)‐CH2‐[16]crown‐5 (1) and Ph2ISnCH2Sn(I)(Ph)‐CH2‐[16]crown‐5 (2) is reported. Both compounds have been characterized by elemental analyses, 1H, 13C, 19F, and 119Sn NMR spectroscopy, and in the case of compound 2also by electrospray ionization mass spectrometry. Single‐crystal X‐ray diffraction analysis revealed for the aqua complex 2⋅H2O trigonal–bipyramidal‐configured tin atoms with intramolecular Sn(1)O(1) and Sn(2)O(1W) distances of 2.555(2) and 2.440(3) Å, respectively. The water molecule is trapped in a sandwich‐like fashion between the crown ether oxygen atoms O(2) and O(4) and the Sn(2) atom. NMR spectroscopy unambiguously proved the ability of compound 2in acetonitrile to overcome the high lattice energy of sodium fluoride and to complex the latter under charge separation.

The synthesis and molecular structure of the novel phosphonic acid 4‐tert‐Bu‐2,6‐Mes2‐C6H2P(O)(OH)2(1) is reported. Compound 1crystallizes in form of its monohydrate as a hydrogen‐bonded cluster (1·H2O)4comprizing four phosphonic acid molecules (O···O 2.383(3)‐3.006(4) Å). Additionally, sterically hindered terphenyl‐substituted phosphorus compounds of the type 4‐tert‐Bu‐2,6‐Mes2‐C6H2PR(O)(OH) (5, R = H; 7, R = O2CC6H4‐3‐Cl; 9, R = OEt) were prepared, which all show dimeric hydrogen‐bonded structures with O···O distances in the range 2.489(2)–2.519(3) Å. Attempts at oxidizing 5using H2O2, KMnO4, O3, or Me3NO in order to give 1failed. Crystallization of 5in the presence of Me3NO gave the novel hydrogen bonded aggregate 4‐tert‐Bu‐2,6‐Mes2‐C6H2PH(O)(OH)·ONMe3(6) showing an O–H···O distance of 2.560(4) Å.

The syntheses and molecular structures of the bromo-substituted triarylphosphane sulfide (3-Br-5-t-Bu-C6H3)P(S)Ph2(1), the arylphosphonic acid di-isopropyl ester 3-t-Bu-5-P(S)Ph2-C6H3P(O)(O-i-Pr)2(2), its triphenyltin derivative 5-t-Bu-3-P(S)Ph2-2-(SnPh3)-C6H2P(O)(O-i-Pr)2(3), and the corresponding triorganostannylium salt 4-t-Bu-2-P(O)(O-i-Pr)2-6-P(S)Ph2-C6H2SnPh2PF6-(4) are reported. By reaction with bromide ion, the latter is converted in situ to the intramolecularly coordinated benzoxaphosphastannole derivative 1(P),3(Sn)-SnPh2OP(O)(O-i-Pr)-6-t-Bu-4-P(S)Ph2C6H2(5). Ab initio MO calculations on the ethoxy-substituted analogue of compound 4indicate a reduced positive charge at the tin atom in comparison with previously reported 4-t-Bu-2,6-P(O)(OEt)22C6H2SnPh2PF6-.

The hypercoordinated di- and triorganotin(IV) chlorides [{2-(Me2NCH2)C6H4}2SnCl2] (1a) and [{2-(Me2NCH2)C6H4}R2SnCl] [R = Me (2a), Ph (3a)] were prepared by treating SnCl4 or R2SnCl2 with [Li{2-(Me2NCH2)C6H4}]. Halide-exchange reactions between the organotin(IV) chlorides and the appropriate potassium halides gave [{2-(Me2NCH2)C6H4}2SnX2] [X = F (1b), I (1d)], [{2-(Me2NCH2)C6H4}Me2SnX] [X = F (2b), Br (2c), I (2d)] and [{2-(Me2NCH2)C6H4}Ph2SnX] [X = F (3b), I (3d)]. Their solution behaviour was investigated by multinuclear (1H, 13C, 19F and 119Sn) NMR spectroscopy, including variable-temperature studies. Single-crystal X-ray diffraction analyses revealed that the strong intramolecular coordination of the nitrogen atom from the pendant CH2NMe2 group to tin induces chirality. The influence of the identity and the number of the halogen atoms and the organic substituents at tin is discussed in relation with the hydrogen-bonding network, which results in different supramolecular architectures in the crystal. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

The reaction of the bismuth silanolates [Bi(OSiR2R′)3] (R = R′ = Me, Et, iPr; R = Me, R′ = tBu) with water has been studied. Partial hydrolysis gave polynuclear bismuth‐oxo clusters whereas amorphous bismuth‐oxo(hydroxy) silanolates were obtained when an excess of water was used in the hydrolysis reaction. The metathesis reaction of BiCl3with NaOSiMe3provided mixtures of heterobimetallic silanolates. The molecular structures of [Bi18Na4O20(OSiMe3)18] (2), [Bi33NaO38(OSiMe3)24]⋅3 C7H8(3⋅3 C7H8), [Bi50Na2O64(OH)2(OSiMe3)22]⋅2 C7H8⋅2 H2O (4⋅2 C7H8⋅2 H2O), [Bi4O2(OSiEt3)8] (5), [Bi9O7(OSiMe3)13]⋅0.5 C7H8(6⋅0.5 C7H8), [Bi18O18(OSiMe3)18]⋅2 C7H8(7⋅2 C7H8) and [Bi20O18(OSiMe3)24]⋅3 C7H8(8⋅3 C7H8) are presented and compared with the solid‐state structures of [Bi22O26(OSiMe2tBu)14] (9) and β‐Bi2O3. Compound 2crystallises in the triclinic space group P$\bar 1$with the lattice constants a= 17.0337(9), b= 19.5750(14), c= 26.6799(16) Å, α= 72.691(4), β= 73.113(4) and γ= 70.985(4)°; compound 3⋅3 C7H8crystallises in the monoclinic space group P21/nwith the lattice constants a= 20.488(4), b= 22.539(5), c= 26.154(5) Å and β= 100.79(3)°; compound 4⋅2 C7H8⋅2 H2O crystallises in the monoclinic space group P21/nwith the lattice constants a= 20.0518(12), b= 24.1010(15), c= 27.4976(14) Å and β= 103.973(3)°; compound 5crystallises in the monoclinic space group P21/cwith the lattice constants a= 25.256(5), b= 15.372(3), c= 21.306(4) Å and β= 113.96(3)°; compound 6⋅0.5 C7H8crystallises in the triclinic space group P$\bar 1$with the lattice constants a= 15.1916(9), b= 15.2439(13), c= 22.487(5) Å, α= 79.686(3), β= 74.540(5) and γ= 66.020(4)°; compound 7⋅2 C7H8crystallises in the triclinic space group P$\bar 1$with the lattice constants a= 14.8295(12), b= 16.1523(13), c= 18.4166(17) Å, α= 75.960(4), β= 79.112(4) and γ= 63.789(4)°; and compound 8⋅3 C7H8crystallises in the triclinic space group P$\bar 1$with the lattice constants a= 17.2915(14), b= 18.383(2), c= 18.4014(18) Å, α= 95.120(5), β= 115.995(5) and γ= 106.813(5)°. The molecular structures of the bismuth‐rich compounds are related to the CaF2‐type structure. Formally, the hexanuclear [Bi6O8]2+fragment might be described as the central building unit, which is composed of bismuth atoms placed at the vertices of an octahedron and oxygen atoms capping the trigonal faces. Depending on the reaction conditions and the identity of R, the thermal decomposition of the hydrolysis products [BinOl(OH)m(OSiR3)3n−(2l−m)] gives α‐Bi2O3, β‐Bi2O3, Bi12SiO20or Bi4Si3O12.

The reaction of [Bi(OtBu)3] with LiOSiMe3 gave the heterobimetallic bismuth-oxo cluster [Bi3Li5(μ5-O)2(μ3-OSiMe3)2(μ3-OtBu)2(μ2-OtBu)6] (1) after elimination of Me3SiOSiMe3. The cage compound 1 is the first example of a mixed-metal alkoxide/siloxide composed of lithium and bismuth. Crystals of 1·2 C7H8 and 1·1.5 THF suitable for X-ray single crystal structure analysis were obtained by crystallisation from toluene and THF, respectively. Both solvates crystallise in the orthorhombic space group Pmmn with Z = 2. The lattice constants are a = 16.267(3) Å, b = 17.126(3) Å and c = 12.155(2) Å (1·2 C7H8) and a = 16.353(2) Å, b = 17.156(1) Å and c = 12.256(1) Å (1·1.5 THF). In both compounds the solvent molecules occupy channels along the c-axis. The basic molecular unit is best described as a face-sharing double cubane [BiLi5(μ4-O)2(μ3-OSiMe3)2(μ3-OtBu)2] which is coordinated by two [Bi(OtBu)3] molecules. The compound is kinetically labile in solution and readily decomposes in 1,1,2,2-tetrachloroethane with elimination of 1,1,2-trichloroethylene. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

The novel heterobimetallic sodium-bismuth-oxo clusters [Bi2Na4O(OSiMe3)8] (1), [Bi10Na5O7(OH)6(OSiMe3)15]·1.5C7H8 (2·1.5C7H8), [Bi15Na3O18(OSiMe3)12]·C7H8 (3·C7H8) and [Bi14Na8O18(OSiMe3)14(THF)4]·C6H6 (4·C6H6) were prepared starting from BiCl3 and NaOSiMe3. Compound 1 crystallises in the trigonal space group R$\bar {3}$c with the lattice constants a = 12.8844(3) Å and c = 54.6565(3) Å, compound 2·1.5C7H8 crystallises in the triclinic space group P$\bar {1}$ with the lattice constants a = 15.0377(2) Å, b = 16.0373(2) Å, c = 27.8967(5) Å, α = 87.1321(6)°, β = 86.6530(7)° and γ = 63.6617(6)°, compound 3·C7H8 crystallises in the monoclinic space group C2/c with the lattice constants a = 54.311(11), b = 19.846(4), c = 22.885(5) Å and β = 112.32(3)°, and compound 4·C6H6 crystallises in the trigonal space group R$\bar {3}$ with the lattice constants a = 15.9786(4) Å and c = 46.8329(17) Å. The formation of M–O–M bonds results from both partial hydrolysis followed by condensation as well as from elimination of Me3SiOSiMe3 from M–OSiMe3 groups. The hexanuclear metal-oxo silanolate 1 is more conveniently synthesised by the addition of NaOSiMe3 to a toluene solution of in situ-prepared [Bi(OSiMe3)3]. The metal-oxo(hydroxo) silanolates differ significantly in composition, but show similar building units. Thermal decomposition of the metal-oxo silanolates in the solid state gave heterogeneous decomposition products containing bismuth silicates. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

The bismuth tris(triorganosilanolates) [Bi(OSiR3)3] (1, R = Me; 2, R = Et; 3, R = iPr) were prepared by reaction of R3SiOH with [Bi(OtBu)3]. Compound 1crystallizes in the triclinic space group $P{\bar 1}$with Z = 2 and the lattice constants a= 10.323(1) Å, b= 13.805(1) Å, c= 21.096(1) Å and α = 91.871(4)°, β= 94.639(3)°, γ= 110.802(3)°. In the solid state compound 1is a trimer as result of weak intermolecular bismuth‐oxygen interactions with Bi–O distances in the range 2.686(6)–3.227(3) Å. The coordination at the bismuth atoms Bi(1) and Bi(3) is best described as 3 + 2 coordination whereas Bi(2) shows a 3 + 3 coordination. The intramolecular Bi–O distances fall in the range 2.041(3)–2.119(3) Å. Compound 3crystallizes in the orthorhombic space group Pbcmwith Z = 4 and the lattice constants a= 7.201(1) Å, b= 23.367(5) Å and c= 20.893(1) Å, whereas the triethylsilyl‐derivative 2is liquid. In contrast to [Bi(OSiMe3)3] (1) compound 3is monomeric in the solid state, but shows similar intramolecular Bi–O distances in the range 1.998(2)–2.065(5) Å. The bismuth silanolates are highly soluble in common organic solvents and strongly moisture sensitive. Compound 1shows the lowest thermal stability.

The reaction of (p‐MeOC6H4)2TeO with two equivalents of HO3SCF3and HO2PPh2provided the tetraorganoditelluroxanes (F3CSO3)(p‐MeOC6H4)2TeOTe(p‐MeOC6H4)2(O3SCF3) (1) and (Ph2PO2)(p‐MeOC6H4)2TeOTe(p‐MeOC6H4)2(O2PPh2)·2 Ph2PO2H (2) in good yields. Compounds 1and 2were characterized by solution and solid‐state 31P and 125Te NMR spectroscopy, IR spectroscopy, electrospray mass spectrometry, conductivity measurements and single crystal X‐ray diffraction. In solution, compound 1undergoes an electrolytic dissociation and reversibly reacts with traces of water to give the mononuclear cation [(p‐MeOC6H4)2TeOH]+and triflate anions. Theoretical aspects of the protonation and hydration of model telluroxanes R2TeO (R = H, Me, Ph) were investigated by preliminary DFT calculations and compared to the corresponding selenoxanes R2SeO. The tellurium dihydroxides R2Te(OH)2seem to be more stable than the hydrogen‐bonded complexes R2TeO·H2O.

The syntheses of the organotin-substituted crown ethers m-(Ph2XSnCH2CH2)-15-benzocrown-5 (2, X = Ph; 3, X = I; 4, X = Cl; 5, X = NCS) and the salt [m-(Ph3SnCH2CH2)-15-benzocrown-5·Na]+SCN– (2a) are reported. Compounds 2a and 4 (as its aqua complex 4·H2O) are characterized by single-crystal X-ray diffraction sudies. Multinuclear NMR spectroscopy and electrospray mass spectrometry reveal the triorganotin chloride 4 to be a ditopic host towards sodium rhodanide. This statement is further supported by the ability of compound 4 to transport sodium rhodanide through an organic membrane. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

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The synthesis of [Me2N(CH2)2]2Sn(OSit‐Bu2OH)2(1) by the base‐assisted cohydrolysis of [Me2N(CH2)2]2SnCl2and t‐Bu2SiCl2is described. The molecular structure of 1, determined by single crystal X‐ray diffraction analysis, features a pentacoordinated tin atom owing to the intramolecular coordination of the nitrogen atom of one 3‐dimethylaminopropyl group, and reveals both intramolecular Si(Sn)O···H‐O and intermolecular N···H‐O hydrogen bonding. Compound 1is a rare example of a metallasiloxanol and holds potential for the preparation of multi component oxide materials.

Five coordination compounds of bismuth, lanthanum and praseodymium nitrate with the oxygen‐coordinating chelate ligand (iPrO)2(O)PCH2P(O)(OiPr)2(L) are reported: [Bi(NO3)3(L)2] (1), [La(NO3)3(L)2] (2), [Pr(NO3)3(L)2] (3), [La(NO3)3(L)(H2O)] (4) and [Pr(NO3)3(L)(H2O)] (5). The compounds were characterized by means of single crystal X‐ray crystallography, 1H and 31P NMR spectroscopy in solution, solid‐state 31P NMR spectroscopy, IR spectroscopy, DTA‐TG measurements (1, 2and 4), conductometry and electrospray ionization mass spectrometry (ESI‐MS). In addition, DFT calculations for model compounds of 1and 2support our experimental work. In the solid state mononuclear coordination compounds were observed for 1—3, whereas compounds 4and 5gave one‐dimensional hydrogen‐bonded polymers via water‐nitrate coordination. Despite of the similar ionic radii of bismuth(III), lanthanum(III) and praseodymium(III) for a given coordination number the bismuth and lanthanide compounds 1—3are not isostructural. The bismuth compound 1shows a 9‐coordinate bismuth atom whereas lanthanum(III) and praseodymium(III) atoms are 10‐coordinate in the lanthanide complexes 2—5. The general LnO10coordination motif in compounds 2—5is best described as a distorted bi‐capped square antiprism. The BiO9polyhedron might be deduced from the LnO10polyhedron by replacing one oxygen ligand with a stereochemically active lone pair. The one‐to‐one complexes 4and 5dissociate in solution to give the corresponding one‐to‐two complexes 2and 3, respectively, and solvated Ln(NO3)3. In contrast to the lanthanides, the one‐to‐two bismuth complex 1is less stable in CH3CN solution and partially dissociates to give solvated Bi(NO3)3and (iPrO)2(O)PCH2P(O)(OiPr)2.

The synthesis of the α,ω-bisdichlorotrimethylsilylmethylstannylalkanes, Me3SiCH2Cl2SnCH2nSnCl2CH2SiMe313, n  5; 14, n  6; 15, n  7; 16, n  8; 17, n  10; 18, n  12 and the corresponding oligomethylene-bridged diorganotin oxides Me3SiCH2OSnCH2nSnOCH2SiMe3m19, n  5; 20, n  6; 21, n  7; 22, n  8; 23, n  10; 24; n  12 is reported. The reaction of the diorganodichlorostannanes 13–18with the corresponding diorganotin oxides 19–24provided the spacer-bridged tetraorganodistannoxanes Me3SiCH2ClSnCH2nSnClCH2SiMe3O425, n  5; 26, n  6; 27, n  7; 28, n  8; 29, n  10; 30, n  12. Compounds 13–30have been identified by elemental analyses and multinuclear NMR spectroscopy. Compounds 25, 27, 29and 30have also been characterised by single crystal X-ray diffraction analysis and electrospray mass spectrometry. For the latter the essential double ladder motif is maintained for all nin the solid state, but subtle changes in alignment of the ladder planes occur. Separation between the two layers of the double ladder ranges from approx. 8.7 for 25, n  5 to approx. 15 for 30, n  12. In solution there is some dissociation of the double ladders into the corresponding dimers. The degree of dissociation is favoured by increasing oligomethylene chain length n.

The synthesis of the α,ω-bis[dichloro(trimethylsilylmethyl)stannyl]alkanes, (Me₃SiCH₂)Cl₂Sn(CH₂)_nSnCl₂(CH₂SiMe₃) (13, n = 5; 14, n = 6; 15, n = 7; 16, n = 8; 17, n = 10; 18, n = 12) and the corresponding oligomethylene-bridged diorganotin oxides [(Me₃SiCH₂)(O)Sn(CH₂)_nSn(O)(CH₂SiMe₃)]_m (19, n = 5; 20, n = 6; 21, n = 7; 22, n = 8; 23, n = 10; 24; n = 12) is reported. The reaction of the diorganodichlorostannanes 13–18 with the corresponding diorganotin oxides 19–24 provided the spacer-bridged tetraorganodistannoxanes {[(Me₃SiCH₂)ClSn(CH₂)_nSnCl(CH₂SiMe₃)]O}₄ (25, n = 5; 26, n = 6; 27, n = 7; 28, n = 8; 29, n = 10; 30, n = 12). Compounds 13–30 have been identified by elemental analyses and multinuclear NMR spectroscopy. Compounds 25, 27, 29 and 30 have also been characterised by single crystal X-ray diffraction analysis and electrospray mass spectrometry. For the latter the essential double ladder motif is maintained for all n in the solid state, but subtle changes in alignment of the ladder planes occur. Separation between the two layers of the double ladder ranges from approx. 8.7 Å (for 25, n = 5) to approx. 15 Å (for 30, n = 12). In solution there is some dissociation of the double ladders into the corresponding dimers. The degree of dissociation is favoured by increasing oligomethylene chain length n.

The trinuclear organotin−oxo cluster [Ph2P(OSntBu2)2O· tBu2Sn(OH)2][O3SCF3] (6), was prepared in good yield by the consecutive reaction of (tBu2SnO)3 with F3CSO3H and Ph2PO2H, and adopts a common tricyclic ESn3O3X2 structural motif with E = P; X = OH, similar to those found in the recently reported species [M(OSntBu2)2O·tBu2Sn(OH)2] [M = Ph2Si (1), Me2Si (2), CO (3), MesB (4)] and [Ph2Si(OSntBu2)2O·tBu2SnF2] (5) where E = Si, C, B and X = OH, F. Compound 6 was characterized by multinuclear NMR spectroscopy, IR spectroscopy, electrospray mass spectrometry and single-crystal X-ray diffraction analysis. A natural population analysis (NPA) performed on the B3LYP/LANL2DZ level of theory for the molecular structures of the isoelectronic species [Ph2Si(OSntBu2)2O·tBu2Sn(OH)2] (1) and [Ph2P(OSntBu2)2O·tBu2Sn(OH)2]⁺ (6a) suggests that the positive charge of the latter is partially delocalised over the phenyl rings. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

The intramolecularly coordinated heteroleptic organolead(II) compounds {4-tBu-2,6-[P(O)(OEt)2]2C6H2}PbX (2, X = Cl; 3, X = SPh) have been synthesized. Single-crystal X-ray analyses reveal that both compounds adopt polymeric chain structures by intermolecular Pb−X···Pb bridges, a structural motif previously unknown for organolead(II) derivatives. Compound 2 reacts with lithium diisopropylamide, iPr2NLi, and lithium bis(trimethylsilyl)methane, (Me3Si)2CHLi, respectively, to provide in situ the corresponding organolead(II) compounds {4-tBu-2,6-[P(O)(OEt)2]2C6H2}PbX (4, X = iPr2N; 5, X = (Me3Si)2CH], which were identified by NMR spectroscopy but could not be obtained as analytically pure substances. Attempts to isolate the intramolecularly coordinated organolead(II) hexafluorophosphate {4-tBu-2,6-[P(O)(OEt)2]2C6H2}Pb⁺PF6⁻ from the reaction of 2 with TlPF6 also failed. Instead, the unprecedented salt [{5-tBu-1,3-[P(O)(OEt)2]2C6H3}4·(Pb2F)] [PF6]3·4THF (6) was obtained, in which the [(Pb−F−Pb)]³⁺ cation is stabilized by eight intermolecular P=O&rlarr2;Pb interactions. Compound 6 was characterized by single-crystal X-ray analysis and electrospray mass spectrometry. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Die Reaktion von M[BF4] (M = Li, K) mit (CH3)3SiCN führt je nach Reaktionsdauer und Temperatur selektiv zu den gemischten Cyanofluoroboraten M[BFx(CN)4—x] (x = 1, 2; M = Li, K). Unter Verwendung von (C2H5)2O·BF3gelingt die Synthese von (CH3)3SiNCBFx(CN)3—x(x = 0, 1). Die Charakterisierung der beschriebenen Verbindungen erfolgt anhand von Schwingungs‐ und NMR‐Spektren sowie durch Röntgenstrahlbeugung an Einkristallen: Li[BF2(CN)2]·2Me3SiCN Cmc21, a = 24.0851(5), b = 12.8829(3), c = 18.9139(5) Å, V = 5868.7(2) Å3, Z = 12, R1= 4, 7%; K[BF2(CN)2] P41212, a = 13.1596(3), c = 38.4183(8) Å, V = 6653.1(3) Å3, Z = 48, R1= 2, 5%; K[BF(CN)3] P1, a = 6.519(1), b = 7.319(1), c = 7.633(2) Å, α = 68.02(3), β = 74.70(3), γ = 89.09(3)°, V = 324.3(1) Å3, Z = 2, R1= 3.6%; Me3SiNCBF(CN)2Pbca, a = 9.1838(6), b = 13.3094(8), c = 16.840(1)Å, V = 2058.4(2)Å3, Z = 8, R1= 4, 4%

The structure of tert-butylphosphonic acid in the solid, in solution, and in the gas phase was studied by single-crystal X-ray diffraction, ¹H and ³¹P NMR spectroscopic studies in solution, solid-state ³¹P NMR spectroscopy, and electrospray ionization mass spectrometry. In addition, density functional theory (DFT) calculations at the B3LYP/6-31G*, B3LYP/6-31+G*, and B3LYP/6-311+G* level of theory for a large number of H-bonded aggregates of the type (tBuPO3H2)n (Cn, Pn; n=1–7) support the experimental work. Crystallization of tBuPO3H2 from polar solvents such as CH3CN or THF gives the H-bonded one-dimensional polymer 2, whereas crystallization from the less polar solvent CDCl3 favors the formation of the H-bonded cluster (tBuPO3H2)6·CDCl3 (1). In CDCl3 the hexamer (tBuPO3H2)6 (C6) is replaced by smaller aggregates down to the monomer with decreasing concentration. DFT calculations and natural bond orbital (NBO) analyses for the clusters C1–C7 and the linear arrays P1–P7 reveal the hexamer C6 to be the energetically favored structure resulting from cooperative strengthening of the hydrogen bonds in the H-bonded framework. However, the average hydrogen bond strengths calculated for C6 and P2 do not differ significantly (42–43 kJ mol⁻¹). The average distances rO···O, rO&bond;H, rP&dbond;O, and rP&bond;OH in C1–C7 and P1–P7 are closely related to the hydrogen bond strength. Electrospray ionization mass spectrometry shows the presence of different anionic species of the type [(tBuPO3H2)n-H]⁻ (A1–A7, n=1–7) depending on the instrumental conditions. DFT calculations at the B3LYP/6-31G* level of theory were carried out for A1–A6. We suggest the dimer [(tBuPO3H2)2-H]⁻ (A2) and the trimer [(tBuPO3H2)3-H]⁻ (A3) are the energetically favored anionic structures. A hydrogen bond energy of approximately 83 kJ mol⁻¹ was calculated for A2. Electrospray ionization mass spectrometry is not suitable to study the assembling process of neutral H-bonded tert-butylphosphonic acid since the removal of a proton from the neutral aggregates has a large influence on the hydrogen bond strength and the cluster structure.

The structure of tert‐butylphosphonic acid in the solid, in solution, and in the gas phase was studied by single‐crystal X‐ray diffraction, 1H and 31P NMR spectroscopic studies in solution, solid‐state 31P NMR spectroscopy, and electrospray ionization mass spectrometry. In addition, density functional theory (DFT) calculations at the B3LYP/6‐31G*, B3LYP/6‐31+G*, and B3LYP/6‐311+G* level of theory for a large number of H‐bonded aggregates of the type (tBuPO3H2)n(Cn, Pn; n=1–7) support the experimental work. Crystallization of tBuPO3H2from polar solvents such as CH3CN or THF gives the H‐bonded one‐dimensional polymer 2, whereas crystallization from the less polar solvent CDCl3favors the formation of the H‐bonded cluster (tBuPO3H2)6⋅CDCl3(1). In CDCl3the hexamer (tBuPO3H2)6(C6) is replaced by smaller aggregates down to the monomer with decreasing concentration. DFT calculations and natural bond orbital (NBO) analyses for the clusters C1–C7and the linear arrays P1–P7reveal the hexamer C6to be the energetically favored structure resulting from cooperative strengthening of the hydrogen bonds in the H‐bonded framework. However, the average hydrogen bond strengths calculated for C6and P2do not differ significantly (42–43 kJ mol−1). The average distances rO⋅⋅⋅O, rOH, rPO, and rPOHin C1–C7and P1–P7are closely related to the hydrogen bond strength. Electrospray ionization mass spectrometry shows the presence of different anionic species of the type [(tBuPO3H2)n‐H]−(A1–A7, n=1–7) depending on the instrumental conditions. DFT calculations at the B3LYP/6‐31G* level of theory were carried out for A1–A6. We suggest the dimer [(tBuPO3H2)2‐H]−(A2) and the trimer [(tBuPO3H2)3‐H]−(A3) are the energetically favored anionic structures. A hydrogen bond energy of approximately 83 kJ mol−1was calculated for A2. Electrospray ionization mass spectrometry is not suitable to study the assembling process of neutral H‐bonded tert‐butylphosphonic acid since the removal of a proton from the neutral aggregates has a large influence on the hydrogen bond strength and the cluster structure.

The synthesis and complete characterization by multinuclear NMR, infrared, and Mössbauer spectroscopy, by single crystal X-ray analysis, as well as by electrospray mass spectrometry of the new soluble triorganotin fluoride Me2PhSnF (1) is reported. The crystal structure of 1 reveals a rod-like polymeric structure in the solid state. Solutions of 1 in apolar solvents, such as toluene, contain mixtures of interconvertible oligomers. Ab initio MO calculations on model compounds H3SnF, [H3SnFSnH3]⁺, and [FH3SnFSnH3F]⁻ indicate that the Sn−F bonds are substantially ionic in character, and suggest open-chain species, rather than cyclic species. In donor solvents, such as pyridine, 1 forms complexes with the solvent, such as Me2PhSnF·pyridine. The solid-state structure of (Me3SiCH2)3SnF (2) is reformulated as monomeric with a weak intermolecular Sn···F interaction that gives rise to a [4+1] coordination. The relative short Sn−Sn separation enables the fluorine atoms to oscillate (flip-flop) between two neighboring (Me3SiCH2)3Sn− groups, which is expressed in the X-ray experiment by a dynamic disorder. Ab initio MO calculations on a model compound, [H3SnFSnH3]⁺, suggest only a small energy barrier for the flip-flop motion. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2003)

The dimeric tetraorganodistannoxane [n‐Bu2(F)SnOSn(F)t‐Bu2]2(1) was prepared by the reaction of (t‐Bu2SnO)3with n‐Bu2SnF2and characterized in solution by multinuclear NMR spectroscopy and ESI MS spectrometry and in the solid state by 119Sn MAS NMR spectroscopy and single crystal X‐ray diffraction.

The reaction of the organolithium derivative {2, 6‐[P(O)(OEt)2]2‐4‐tert‐Bu‐C6H2}Li (1‐Li) with [Ph3C]+[PF6]—gave the substituted biphenyl derivative 4‐[(C6H5)2CH]‐4′‐[tert‐Bu]‐2′, 6′‐[P(O)(OEt)2]2‐1, 1′‐biphenyl (5) which was characterized by 1H, 13C and 31P NMR spectroscopy and single crystal X‐ray analysis. Ab initioMO‐calculations reveal the intramolecular O···C distances in 5of 2.952(4) and 2.988(5)Å being shorter than the sum of the van der Waals radii of oxygen and carbon to be the result of crystal packing effects. Also reported are the synthesis and structure of the bromine‐substituted derivative {2, 6‐[P(O)(OEt)2]2‐4‐tert‐Bu]C6H2}Br (9) and the structure of the protonated ligand 5‐tert‐Bu‐1, 3‐[P(O)(OEt)2]2C6H3(1‐H). The structures of 1‐H, 5, and 9are compared with those of related metal‐substituted derivatives.

The syntheses and molecular structures, as determined by single‐crystal X‐ray diffraction analysis, of the first intramolecularly [4+2]‐coordinated tetraorganolead compound {4‐t‐Bu‐2, 6‐[P(O)(OEt)2]2C6H2}PbPh3(2) and the triphenyllead chloride adduct of the first intramolecularly coordinated benzoxaphosphaplumbole {[1(Pb), 3(P)‐Pb(Ph)2OP(O)(OEt)‐5‐t‐Bu‐7‐P(O)(OEt)2]C6H2·Ph3PbCl} (3a) are reported. The reaction of 2with [Ph3C]+[PF6]—and p‐MeC6H4SO3H, respectively, provides the triorganolead salts {4‐t‐Bu‐2, 6‐[P(O)(OEt)2]2C6H2}PbPh2+X—(4, X = PF6; 4a, X = p‐MeC6H4SO3). Reaction of 2with bromine and hydrogen chloride, respectively, gives the diorganolead dihalides {4‐t‐Bu‐2, 6‐[P(O)(OEt)2]2C6H2}PbPhX2(5, X = Br; 6, X = Cl).

The title compound was obtained as thin needles from a complex reaction mixture at low temperature. According to the single crystal X‐ray structure analysis it crystallizes in the triclinic space group P1¯ and consists of solvent separated cations and anions. As a result of hydrogen‐bonding a one‐dimensional polymer is formed with short O···O distances in the range 2.458(4)—2.709(3)Å.

Die Reaktion von Hg(NO3)2mit K[B(CN)4] führt zu Hg[B(CN)4]2(1). Eine Komproportionierungsreaktion von 1mit elementaren Quecksilber liefert das entsprechende Quecksilber(I)‐Salz Hg2[B(CN)4]2(2). Die Charakterisierung von 1und 2erfolgt anhand von Schwingungsspektren, 13C‐ und 11B‐NMR‐Spektren sowie der Auswertung von Kristallstrukturanalysen. Hg[B(CN)4]2kristallisiert trigonal in der Raumgruppe P3¯m1 mit a = 781.75(3) pm, c = 601.68(2) pm, V = 318.44(2)Å3und einer Formeleinheit in der Elementarzelle. Für Hg2[B(CN)4]2wird eine orthorhombische Elementarzelle der Raumgruppe Pbcm mit a = 568.9(1) pm, b = 3280.9(7) pm, c = 601.68(2) pm, V = 1389.6(5)Å3und Z = 4 gefunden.