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A series of new homo- and heterometallic lithium and lithium/lanthanide disiloxanediolate complexes were prepared and fully characterized. Three new adducts of dilithium tetraphenyldisiloxanediolate, [(Ph2SiOLi)2O] (2), with simple Lewis bases (Et2O, THF, DME) were prepared by treatment of Ph2Si(OH)OSiPh2(OH) (1) with 2 equiv. of n-butyllithium in the respective donor solvent. This way the adducts [{Ph2SiOLi(Et2O)}2O]2 (3), [{Ph2SiOLi(THF)}2O]2 (4), and [{Ph4Si2O(OLi)2}2(DME)3]∞ (5a) were obtained in a straightforward manner and in nearly quantitative yields. Treatment of anhydrous lanthanide(III) chlorides LnCl3 (Ln = Tb, Lu) with 2 equiv. of 2 in THF afforded the new lanthanide(III) bis(disiloxanediolate) complexes [{(Ph2SiO)2O}2{Li(THF)2}2]TbCl (6) and [{(Ph2SiO)2O}2{Li(THF)2}2]LuCl (7) in high yields. Similar reactions of LnCl3 (Ln = Ce, Nd) with 3 equiv. of 2 provided the heterometallic Li/Ln tris(disiloxanediolate) complexes [{(Ph2SiO)2O}3{Li(DME)}2{Li(THF)}]Ce (8) and [{(Ph2SiO)2O}3{Li(DME)}{Li(Et2O)}{Li(THF)}]Nd (9). All title compounds were structurally characterized through single-crystal X-ray diffraction.

This review provides an overview of the precursor chemistry that has been developed around the phase-change material germanium-antimony-telluride, Ge2Sb2Te5 (GST). Thin films of GST can be deposited by employing either chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques. In both cases, the success of the layer deposition crucially depends on the proper choice of suitable molecular precursors. Previously reported processes mainly relied on simple alkoxides, alkyls, amides and halides of germanium, antimony, and tellurium. More sophisticated precursor design provided a number of promising new aziridinides and guanidinates.

The new zirconium bent metallocenes (COT)Zr(CptBu2)Cl (1) and (COT)Zr(Cp′′)Cl (2) were synthesized in a straightforward manner and in high yields (1: 91 %, 2: 86 %) by treatment of in situ-prepared (COT)ZrCl2(THF) with 1 equiv. of K(CptBu2) or K(Cp′′), respectively (COT = η8-cyclooctatetraenyl; CptBu2 = η5-1,3-di-tert-butylcyclopentadienyl; Cp′′ = η5-1,3-bis(trimethylsilyl)cyclopentadienyl). Subsequent reaction of 1 with 1 equiv. of phenyllithium afforded the σ-phenyl derivative (CptBu2)Zr(COT)Ph (3) as orange crystals in 83 % isolated yield. All three new compounds were structurally characterized through single-crystal X-ray diffraction.

The new organotin(IV) squarates and croconates [SnMe2(H2O)2]C4O4 (1), [SnMe3]2C4O4 (2), and [SnMe3(H2O)]2C5O5 (3), were prepared by salt metathesis from the appropriate sodium salts, and characterized by single-crystal X-ray diffraction and infrared spectroscopy. While 1 and 2 are coordination polymers with bridging C4O42– anions, compound 3 exists as a monomer in the solid state. In the hydrated compounds 1 and 3, the molecules are interconnected by various types of O–H···O bridges between non-coordinated carbonyl oxygen atoms and water ligands, resulting in a supramolecular layer (1, 2) or network structure (3), respectively.

The crystal structures of two classical cobalt(III) complexes comprising the [CoCl(NH3)(en)(py)2]2+ cation were determined by single-crystal X-ray diffraction. Both complexes, dark red [CoCl(NH3)(en)(py)2]Cl2·H2O (1) and purple [CoCl(NH3)-(en)(py)2][HgCl4]·1.125H2O (2), crystallize in the triclinic space group P1. In both compounds, the Co atom exhibits a typical octahedral coordination and the configuration index of the complex is OC-6-43. In the case of the chloride (1), the asymmetric unit comprises one formula unit, whereas there are two formula units in the case of the tetrachloridomercurate (2). Complex cations, anions, and crystal water molecules are interconnected by various N–H···N, N–H···Cl, N–H···O, O–H···Cl, and O–H···O bridge bonds. As a result, compound 1 features a two-dimensional layer structure and compound 2 exists as a three-dimensional network.

The reaction of EuI2(THF)2 with 3 equiv. of the recently discovered lithium-cyclopropylethinylamidinate Li[c-C3H5–C≡C–C(NCy)2] (1) (Cy = cyclohexyl) unexpectedly afforded the heterometallic europium(III) amidinate complex [{c-C3H5–C≡C–C(NCy)2}Li{c-C3H5–C≡C–C(NCy)2}2Eu(μ-I)2Li(THF)2] (2) in the form of bright yellow, air- and moisture-sensitive crystals. An X-ray diffraction study of 2 revealed several unusual structural features. It comprises a double “ate” complex of the tentative trivalent europium(III) bis(cyclopropylethinylamidinate) derivative [c-C3H5–C≡C–C(NCy)2]2EuIIII. “Ate” complex formation occurred not only through retention of one equiv. of lithium iodide but also through addition of one equiv. of Li[c-C3H5–C≡C–C(NCy)2]. The Li atom in the iodo-bridged Eu(μ-I)2Li(THF)2 part of the molecule is tetrahedrally coordinated, whereas the second lithium atom is only tricoordinate through the presence of a rare monodentate (dangling) amidinate ligand.

The reaction of RuCl2(PPh3)3 with N-pyrazolylpropanamide (N-ppa) displaces a single PPh3 producing the six-coordinate complex RuCl2(PPh3)2(N-ppa) (1). A crystal structure determination of the dichloromethane solvate RuCl2(PPh3)2(N-ppa)·2CH2Cl2 (1·2CH2Cl2) revealed that the geometry about the central Ru atom is distorted octahedral with the chloride ligands in trans-position and the N-ppa acting as N,O-chelating ligand. In the solid state, RuCl2(PPh3)2(N-ppa) molecules are dimerized via N–H···Cl hydrogen bonds. The dimers pack as chains in the c direction and form voids that are occupied by dichloromethane solvent molecules.

The syntheses and single-crystal X-ray structures of several first-row transition metal complexes containing the multifunctional acrylamide-derived ligand N-pyrazolylpropanamide (1 = L) are reported. The general synthesis involves treatment of appropriate transition metal salts with an excess of 1 in ethanolic solution in the presence of triethylorthoformate as dehydrating agent. This way the perchlorates of iron(II) and cobalt(II) afforded the complexes [L2M(EtOH)2](ClO4)2[M = Fe (2), Co (3), in good yields (82 and 85 %)]. Light green L2NiCl2 (4) was obtained analogously from NiCl2·6H2O. Hydration of 4 afforded the dark green cationic nickel(II) complex [L2Ni(H2O)4]Cl2 (4a). In compounds 2–4 the N-pyrazolylpropanamide acts as N, O-chelating ligand. In contrast, monodentate nitrogen coordination via the pyrazolyl ring was found for the dicoordinate silver(I) complex [L2Ag]NO3·H2O (5). The molecular and crystal structures of 2, 3, 4a, and 5 were determined by X-ray diffraction.

The recently reported cerium(IV) tripodal Schiff-base com- plex (TRENDSAL)CeCl (TRENDSAL = (N{CH2CH2N=CH(C6H2tBu2- 3,5-O-2}3) 3- ) serves as excellent starting material for novel Ce 4+ coordi- nation compounds. The first cerium(IV) azide, (TRENDSAL)CeN3 and

This research report summarizes recent results in the chemistry of lanthanide disiloxanediolates and metallasilsesquioxanes. Both classes of compounds can be regarded as realistic model compounds for silica-supported lanthanide catalysts.

The bright yellow Schiff-base complex Eu(TRENDSAL) (1) (TRENDSAL = N[CH2CH2N=CH(2-OH-3,5-tBu2C6H2)]3) was prepared in 71 % yield by treatment of EuCl3·6H2O simultaneously with 3,5-di-tert-butylsalicylicaldehyde and tris(2-aminoethyl)amine in the presence of triethylamine. X-ray crystal structure analyses of the solvates 1·DME (DME = 1,2-dimethoxyethane) and 1·MeCN demonstrated the tight encapsulation of the Eu3+ ion, allowing not even the “slim” acetonitrile to enter the coordination sphere of europium.

The reaction of (c-C6H11)7Si7O9(ONa)3, prepared in situ from (c-C6H11)7Si7O9(OH)3 (1), and MnCl2(THF)2 in THF solution resulted in formation of the novel heterobimetallic Mn/Na metallasilsesquioxane complex [(c-C6H11)7Si7O9(O3Mn)Na(Et2O)]2·Et2O (2) which was isolated in the form of colorless crystals in 64 % yield. Similar treatment of MnCl2(THF)2 with in situ prepared (c-C6H11)7Si7O9(OLi)3 afforded the unusual tetramanganese silsesquioxane complex [(c-C6H11)7Si7O9(O3Mn2Br)LiBr(THF)(Et2O)]2 (3) in high yield (81 %). Both 2 and 3 were structurally characterized by single-crystal X-ray diffraction.

Treatment of anhydrous YbCl3 with LiN(SiMe3)2 followed by reaction with 1 equivalent of 1,1,3,3,5,5-hexaphenyl-1,3,5-trisiloxanediol afforded the first mono(trisiloxanediolate) complex of a rare earth element. The compound [Ph2Si(OSiPh2O)2]Yb(THF)(μ-Cl)3Li2(THF)3 (1) was isolated in the form of colorless crystals in very high yield (93%). A single-crystal X-ray diffraction study confirmed the presence of an eight-membered inorganic ring system containing ytterbium. Coordination of one THF ligand and retention of two equivalents of lithium chloride lead to formation of an “ate” complex.

μ-Cy8Si8O13}2Ca(DME)Ca(THF)2 )( 2), the first metalla- silsesquioxane derivative of a heavier alkaline earth metal, has been prepared by a reaction of Cy7Si7O9(OH)3 (1) with metallic Ca in liquid ammonia / THF followed by recrystallization from DME. In the course of the reaction ligand rearrangement under formation of the (Cy8Si8O13) dianion takes place. In the dinuclear calcium

The syntheses, spectroscopy and single crystal X-ray structures of the multifunctional acrylamide-derived ligand N-pyr- azolylpropanamide ( L) (1), and its complexes (L2CuCl2 )( 2) and (L4Co3Cl6 )( 3) with copper(II) and cobalt(II) chlorides, respectively, are described. The ligand 1 is easily obtained in one step by the reaction of pyrazole with acrylamide in a 1:1 molar ratio in the presence of trimethylbenzylammonium hydroxide as a basic cata- lyst. The reaction of CuCl2 ·2 H2O with 1 in a 1:2 metal salt:ligand molar ratio in ethanol/-triethylorthoformate solution gave coordi- nation compound 2. The crystal structure of 2 contains two seven- membered chelate rings formed by two nitrogen atoms of the pyr- azolyl groups and two weakly coordinated carbonyl oxygen atoms

The reaction of samarium(II) diiodide with in situ prepared disodium-1,1,3,3-tetraphenyl-1,3-disiloxanediolate, ((Ph2SiONa)2O), afforded the unusual heterobimetallic samarium(III) disiloxanediolate cluster (Me3SiO{μ-Na(THF)}3- Sm{μ-(Ph2SiO)2O}3Na(THF)) (1) in low yield. A single-crystal X-ray structure determination of 1 revealed the presence of a poly- The organometallic chemistry of the rare earth elements continues to be a highly attractive field of research, in particular due to the numerous applications of organolanthanides in catalysis (1) and or- ganic synthesis (2). An increasingly important area focuses on the development of non-cyclopentadienyl organolanthanide complexes (3). In earlier papers we proposed the novel concept of "inorganic lanthanide metallocenes" (4). It was based on the experimental finding, that a new class of heterobimetallic lanthanide disiloxane- diolates (Scheme 1a) shares structural similarities with the well- known bent metallocenes containing pentamethylcyclopentadienyl ( C5Me5) ligands (Scheme 1b). The latter form a large and well investigated class of organolanthanides with many of them displa- ing high catalytic activities in various olefin transformations (1). In both cases two bulky ligands are coordinated to the central lantha- nide ion in a bent arrangement, leaving room for functional groups X( X Cl, N(SiMe3)2, alkyl, H etc.) as well as additional solvent molecules S (S Et2O, THF etc.).

Deprotonation of the readily available organometallic aldehyde derivative [(η4-C7H7CHO)Fe(CO)3] (2) with NaN(SiMe3)2 in benzene solution at ambient temperature afforded the anionic formylcycloheptatrienyl complex Na[(η3-C7H6CHO)Fe(CO)3] (3). The anion is fluxional in solution and displays a unique ambident reactivity towards electrophiles (MeI, Me3SiCl). New substituted [(η4-RC7H6CHO)Fe(CO)3] and [(η4-heptafulvene)Fe(CO)3] complexes have been identified as the products. Treatment of 3 with 0.5 equivalents of dimeric [(COD)RhCl]2 (COD = 1,5-cyclooctadiene) afforded the functionalized Fe-Rh cycloheptatrienyl complex [(μ-C7H6CHO)(CO)3FeRh(COD)] (7) in up to 86 % yield. Carbonylation of 7 under an atmosphere of CO led to facile conversion to the heterobimetallic pentacarbonyl derivative [(μ-C7H6CHO)(CO)3FeRh(CO)2] (8), which is also accessible in lower yield from the direct reaction of 3 with [Rh(CO)2Cl]2.

The reactivity of neodymium diiodide, NdI2 (1), towards organosilicon, -germanium and -tin halides has been investigated. Compound 1 readily reacts with Me3SiCl in DME to give tri- methylsilane (6 %), hexamethyldisilane (4 %) and (Me3Si)2O (19 %). The reaction with Et3SiBr in THF results in formation of Et3SiSiEt3 (17 %) and Et3SiOBu n (34 %). Alkylation of Me3SiCl with Pr n Cl in the presence of 1 in THF affords Me3SiPr n (10 %), Me3SiOBu n (52 %) and Me3SiSiMe3 (1 %). The main product iden- tified in the reaction mixture formed upon interaction of 1 with dichlorodimethylsilane Me2SiCl2 in THF is di-n-butoxydimethyl- silane Me2Si(OBu n )2 (54 %) together with minor amounts of Me2Si(OBu n )Cl. The reaction of 1 with Me3GeBr under the same conditions produces Me3GeGeMe3 (44 %), Me3GeH (3 %), and Me3GeI (7 %). An analogous set of products was obtained in the reaction with Et3GeBr. Treatment of trimethyltin chloride with 1 causes reduction of the former to tin metal (74 %). Me3SnH (7 %) and hexamethyldistannane (11 %) were identified in the volatile products. The reaction of 1 with Me3SiI provides straightforward access to hepta-coordinated NdI3(THF)4 (2), the structure of which was determined by X-ray diffraction.

Acrylamide complexes of metal perchlorates and tetrafluoroborates, [M(OC(NH2)CH=CH2)6][X]2 (M = Fe, Co, Ni, Zn; X = ClO4, BF4), have been prepared and characterized using single crystal X-ray diffraction, IR spectroscopy and elemental analyses. The complexes contain metal(II) cations surrounded by an octahedral array of acrylamide ligands accompanied by the anions. The tetrafluoroborate or perchlorate counter anions do not coordinate to the metal atoms or take part in strong secondary interactions such as hydrogen bonds with coordinated ligands. Single crystal X-ray structures of these complexes prove that the ligands are coordinated exclusively via the carbonyl oxygen atom. Bonding through the nitrogen atom has not been observed in these complexes.

The three (O-methyl)-p-ethoxyphenyldithiophosphonato triphenylphosphine complexes of copper, silver and gold, [(Ph3P)nM{S2P(OMe)C6H4OEt-p}] (M = Cu, n = 2; M = Ag, Au, n = 1) investigated structurally by X-ray diffraction exhibit remarkable structural differences. The copper compound is a four-coordinate chelate monomer with Cu–S 2.4417(6) and 2.5048(6) A; P–Cu–S 104.24(2)–114.01(2)°; Cu–S–P 82.49(3)° and 80.85(2)°. The silver compound is a cyclic dimer with bridging dithiophosphonato ligands and three-coordinate silver atoms [Ag–S 2.5371(5) and 2.6867(5) A; P–Ag–S 122.88(2)° and 122.17(2)°; Ag–S–P 89.32(2)° and 103.56(2)°]. The gold compound is monomeric with linear dicoordinate gold [Au–S 2.3218(6) A; P–Au–S 177.72(2)°, Au–S–P 100.97(3)°].

The reaction of Ln(NO3)3 (Ln = Ce, Tb, or Yb) with Ph2PCH2CH2P(O)Ph2 in various molar ratios produces Ln(NO3)3(OPPh2CH2CH2PPh2)3. X-ray powder diffraction demonstrates that the three compounds are isostructural. Single crystal X-ray diffraction structures were obtained for Ln = Ce and Tb. The compound are isomorphous and crystallize in the trigonal R3c space group. The lanthanide ions are nine-coordinate with three bidentate nitrate ions and three (OPPh2CH2CH2PPh2) ligands coordinated through oxygen. If the coordination sphere is defined by the three lanthanide-nitrogen vectors and the three lanthanide-O(P) bonds, the complexes can be described as facial octahedral. The chemistry of the Ph2P-CH2CH2-P(O)Ph2 - Ln(NO3)3 system appears to be simpler than ones involving simple phosphine oxide ligands.

Metal complexes of manganese(II), iron(II), and nickel(II) chlorides with acrylamide, [M(O-OC(NH2)CH=CH2)4Cl2] (M = Mn (1), Fe (2) and Ni (3)), have been prepared and characterized by single crystal X-ray diffraction, IR spectroscopy and elemental analyses. The complexes crystallize in the cubic space group, . The coordination geometries of the metal centers in all three complexes involve tetragonally distorted octahedral structures with four O-donor atoms of acrylamide bonded in the equatorial positions and two chlorides in the apical positions.

Hitherto unknown 2,4,6-tris(trifluoromethyl)benzyl alcohol (3) was synthesized in 41 % yield by treatment of freshly prepared RFLi (2) with paraformaldehyde (RF = 2,4,6-tris(trifluoromethyl)phenyl). According to an X-ray diffraction study the crystal structure of 3 consists of S6 symmetric cyclic hexamers [2,4,6-(CF3)3C6H2CH2OH]6. Deprotonation of 3 with NaN(SiMe3)2 in toluene afforded the unsolvated sodium alkoxide derivative RFCH2ONa (4). Homoleptic lanthanide alkoxides of the type Ln(OCH2RF)3 (Ln = Nd (5), Sm (6), Yb (7)) were made by treatment of Ln(C5H5)3 with three equivalents of 3. Similar reactions in a 1:1 molar ratio afforded the bis(cyclopentadienyl)lanthanide alkoxide derivatives (C5H5)2Ln(OCH2RF) (Ln = Nd (8), Sm (9), Yb (10)). Synthese, Struktur und Lanthanoidderivative eines ungewohnlichen hexameren Alkohols: [2,4,6-(CF3)3C6H2CH2OH]6 Der bislang unbekannte 2, 4, 6-Tris(trifluoromethyl)benzylalkohol (3) wurde in 41 % Ausbeute durch Umsetzung von frisch hergestelltem RFLi (2) mit Paraformaldehyd synthetisiert (RF = 2,4,6-Tris(trifluoromethyl)phenyl). Nach der Rontgenstrukturanalyse enthalt die Kristallstruktur von 3S6-symmetrische, cyclische Hexamere [2, 4, 6-(CF3)3C6H2CH2OH]6. Deprotonierung von 3 mit NaN(SiMe3)2 in Toluol lieferte das unsolvatisierte Natriumalkoxid RFCH2ONa (4). Homoleptische Lanthanoidalkoxide des Typs Ln(OCH2RF)3 (Ln = Nd (5), Sm (6), Yb (7)) wurden durch Umsetzung von Ln(C5H5)3 mit drei Aquivalenten 3 erhalten. Die gleichen Reaktionen im Molverhaltnis 1:1 lieferten die Bis(cyclopentadienyl)lanthanoidalkoxide (C5H5)2Ln(OCH2RF) (Ln = Nd (8), Sm (9), Yb (10)).

The crystalline lithium N, N′-diorganoamidinates Li[PhC(NR)2] (1: R = c-C6H11, 2: R = iPr) and Li[(CF3)3C6H2C(N-c-C6H11)2] (3) have been obtained by the reaction of phenyllithium or 2, 4, 6-tris(trifluoromethyl)phenyllithium, resp., with diorganocarbodiimides R-N=C=N-R (R = c-C6H11, iPr). These amidinates have been used for the synthesis of the homoleptic lanthanide(III) amidinates [PhC(N-c-C6H11)2]3Ln (4—6: Ln = Pr, Nd, Sm) and [PhC(NiPr)2]3Pr (7). Seven-coordinate Lewis-base adducts of the type [PhC(NSiMe3)2]3Ln(NCPh) (8, 9: Ln = Sm, Eu) have been prepared by addition of benzonitrile to the homoleptic precursors [PhC(NSiMe3)2]3Ln. The compounds 2 (as its THF adduct), 4, 6, 8 and 9 have been structurally characterized by single crystal X-ray analyses. Lanthanoid(III)-amidinate mit sechs- und siebenfach koordinierten Metallatomen Die kristallinen Lithium N, N′-diorganoamidinate Li[PhC(NR)2] (1: R = c-C6H11, 2: R = iPr) und Li[(CF3)3C6H2C(N-c-C6H11)2] (3) wurden durch Reaktion von Phenyllithium bzw. 2, 4, 6-Tris(trifluormethyl)phenyllithium mit den Diorganocarbodiimiden R-N=C=N-R (R = c-C6H11, iPr) erhalten. Diese Amidinate wurden zur Synthese der homoleptischen Lanthanoid(III)amidinate [PhC(N-c-C6H11)2]3Ln (4—6: Ln = Pr, Nd, Sm) und [PhC(NiPr)2]3Pr (7) verwendet. Siebenfach koordinierte Lewis-Basenaddukte des Typs [PhC(NSiMe3)2]3Ln(NCPh) (8, 9: Ln = Sm, Eu) wurden durch Addition von Benzonitril an die homoleptischen Vorstufen [PhC(NSiMe3)2]3Ln dargestellt. Die Verbindungen 2 (als THF-Addukt), 4, 6, 8 und 9 wurden durch Einkristall-Rontgenstrukturanalysen strukturell charakterisiert.