Volume 36, Issue 5-6

This review classifies and analyzes heterooligo- and heteropolynuclear Pt complexes in the presence of non-transition metals as partners. There is a wide variability of metal combinations: Pt 6 M, Pt 2 M 5 , Pt 3 Hg 2 Ru 2 ; Pt 6 M 2 , Pt 4 Zn 4 , Pt 2 Hg 6 , PtHgAu 6 , PtHg 2 Au 5 ; Pt 6 Hg 4 , Pt 3 HgRu 6 , PtHgAu 8 ; Pt 2 Sn 9 , PtHg 2 Au 8 ; Pt 8 Ge 4 , Pt 8 Sn 4 and {PtM} n . The complexes crystallized in the following crystal classes: trigonal, orthorhombic (each 1 example)<tetragonal (6 examples)<triclinic (15 examples)<monoclinic (19 examples). The mean Pt-Pt bond length is 2.770 Å. The mean Pt-M bond length increased in the order 2.430 Å (M=Ga)<2.685 Å (Ge)<2.770 Å (Zn)<2.822 Å (Sn)<2.834 Å (Hg)<2.932 Å (Tl). This review together with the previous parts gives a comprehensive view on heterometallic Pt complexes with non-transition metals.

For the synthesis of metalloid cluster compounds of tin applying the disproportionation reaction of subvalent metastable Sn(I) halides, Si(SiMe 3 ) 3 proved to be the ligand with the highest synthetic potential. However, degradation of the Si(SiMe 3 ) 3 ligand can also lead to cluster enlargement where additional silicon atoms are incorporated into the cluster core. Here we describe the structure and bonding of the novel anionic cluster compound {Sn 10 Si(SiMe 3 ) 2 [Si(SiMe 3 ) 3 ] 4 } 2- 5 , where such a degradation has taken place. Additionally, requirements for the formation of 5 are discussed.

The synthesis of homoleptic gallium(III) bis(dimethylsilyl)amide Ga[N(SiHMe 2 ) 2 ] 3 was attempted via different pathways. A transsilylamination protocol using Ga[N(SiMe 3 ) 2 ] 3 and HN(SiHMe 2 ) 2 was unsuccessfully applied. An unexpected side product, MeGa[N(SiMe 3 )SiMe 2 N(SiMe 3 ) 2 ] 2 , could be obtained from the synthesis of homoleptic gallium(III) bis(trimethylsilyl)amide via GaCl 3 and LiN(SiMe 3 ) 2 . Alkane elimination from Me 3 Ga or Et 3 Ga and HN(SiHMe 2 ) 2 did not lead to the isolation of Ga[N(SiHMe 2 ) 2 ] 3 either. When a salt metathesis route was conducted, reacting GaCl 3 with LiN(SiHMe 2 ) 2 , the silylamido-bridged dimeric hydride complex {H 2 Ga[μ-N(SiHMe 2 ) 2 ]} 2 was obtained. Its further reaction with N,N,N ′, N ′-tetramethylethylendiamine (tmeda) gave the dinuclear, tmeda-bridged {[H 2 GaN(SiHMe 2 ) 2 ] 2 (μ-tmeda)}.

Complexes of Sn(II), Sn(IV), Ge(IV), and Si(IV) with the ambidentate pyridine-2-thiolato ligand (PyS - ) were synthesized and characterized by multinuclear NMR spectroscopy and single-crystal X-ray diffractometry. Comparison of the structures of E(PyS) 2 Cl 2 (E=Sn, Ge, Si) and E(PyS) 4 (E=Sn, Si) allows for insights into the group 14 coordination chemistry of this ambidentate chelator in dependence of the thiophilicity of the central atom of the corresponding complex. Furthermore, the crystal structure of Sn(PyS) 2 reveals two different coordination modes of its constituents, i.e., the crystal packing features cyclic dimers and polymeric chains of Sn(PyS) 2 . This compound was shown to undergo oxidative addition of 2,2′-dipyridyldisulfide and sulfur with the formation of Sn(PyS) 4 and (PyS) 2 Sn(μ-S) 2 Sn(PyS) 2 , respectively.

The reaction of the arylphosphonic acid esters 4,4′-[( i -PrO) 2 P(O)]C 6 H 4 C 6 H 4 [P(O)(O i- Pr) 2 ] ( L 1 ), 1,3,5-[( i- PrO) 2 P(O)] 3 C 6 H 3 ( L 2 ), and 5- t- Bu-1,3-[( i- PrO) 2 P(O)] 2 C 6 H 3 ( L 3 ), respectively, with bismuth halides BiX 3 (X=Cl, Br, I) gave seven novel bismuth coordination polymers that have been characterized by single-crystal X-ray diffraction analysis. The solid-state structures of [(BiCl 3 )( L 1 )] ( 1 ), [(BiBr 3 )( L 1 )]·0.25CH 3 CN ( 2 ·0.25CH 3 CN), [(BiI 3 ) 2 ( L 1 )]·0.25CH 3 CN ( 3 ·0.25CH 3 CN), [(BiCl 3 )( L 2 )] ( 4 ), [(BiCl 3 ) 2 ( L 2 )] ( 5 ), [(BiBr 3 ) 2 ( L 2 )]·CH 3 CN ( 6 ·CH 3 CN), and [(BiCl 3 )( L 3 )] ( 7 ) are presented. Thermal analysis of [(BiCl 3 ) 2 ( L 2 )] ( 5 ) is indicative of a conversion of the complexes into a bismuth phosphonate by complete i -PrX elimination, whereas for [(BiBr 3 ) 2 ( L 2 )] ( 6 ), elimination of i- PrBr and BiBr 3 is assumed. Compounds 1 – 3 form one-dimensional coordination polymers, whereas two-dimensional networks are observed for compounds 4 – 7 .

The surfactant-free synthesis of β-phase germanium dioxide nanoparticles in ortho -methoxy benzyl alcohol and benzyl alcohol has been reported. Characterisation of the hexagonal β-GeO 2 crystals, which involves powder X-ray diffraction, nitrogen adsorption measurements (Brunauer-Emmett-Teller method), dynamic light scattering measurements, IR spectroscopy, transmission electron microscopy and energy-dispersive X-ray analysis has been presented. Synthesis of β-GeO 2 under ambient conditions in benzyl alcohol results in nanoparticles with diameters below 20 nm, whereas the synthesis under inert conditions in benzyl alcohol at reflux (205°C) gives larger nanoparticles. In ortho -methoxy benzyl alcohol, agglomerates with particle sizes above 100 nm are observed under inert atmosphere conditions at room temperature.

Two new benzene tricarboxylato derivatives [(Cy 2 NH 2 )] 3 [C 6 H 3 (CO 2 ) 3 ]·4H 2 O ( 1 ) and [ i -Bu 2 NH 2 ][(Me 3 SnO 2 C) 2 C 6 H 3 CO 2 ] ( 2 ) have been synthesized and characterized by X-ray crystallography. In the solid state, compound 1 shows a three-dimensional structure involving intra- and intermolecular hydrogen bonds, whereas the X-ray structure of 2 consists of pentacoordinated Sn centers bonded to three methyl groups and two O atoms in a trans -O 2 SnC 3 environment, bridged by oxyanions leading to a layered structure; the cation is involved in intramolecular hydrogen bonds.

The title compound [ n -Pr 2 NH 2 ] 2 [(C 2 O 4 ) 2 SnPh 2 ] ( 1 ) has been synthesized by allowing Ph 2 SnCl 2 to react with [ n -Pr 2 NH 2 ] 2 C 2 O 4 . In 1 , characterized using X-ray crystallography, the Sn atom is six-coordinated by two phenyl groups and four oxygen atoms belonging to two asymmetrically chelating oxalate ligands. The geometry is cis octahedral about tin. In the structure of 1 , there are two [(C 2 O 4 ) 2 SnPh 2 ] 2- moieties differentiated by their ∠C-Sn-C angles [105.07° (15°) and 107.43° (16°)]. These similar, but distinct, anions are connected by [ n -Pr 2 NH 2 ] + cations through N-H···O hydrogen bonds leading to two infinite alternating chains (1) and (2), which loosely assemble via π-π stacking between phenyl groups of adjacent molecules to generate an overall layered structure.

The title compound, isobutyltin(IV) dichloride hydroxide N , N -dimethylformamide solvate {[iBuSnCl 2 (OH)(DMF)] 2 }, an accidental side product from the reaction of isobutyltin(IV) trichloride with moisture in N,N -dimethylformamide, exhibits structural features similar to those of the corresponding hydrates of monoorganotin(IV) dihalide hydroxides characterized by a central four-membered rhombic Sn-O ring and tin atoms with a distorted octahedral coordination.