W. Wojnowski

Contributions to the chemistry of silicon-sulphur compounds—LX. Synthesis, molecular structure and properties of the dimeric cadmium(II) bis(tri-tert-butoxysilanethiolate) (t-C4H9O)3SiS2Cd2

Abstract The preparation and X-ray crystal structure of cadmium(II) bis(tri-tert-butoxysilanethiolate) from tri-tert-butoxysilanethiol and cadmium acetate are described. The compound forms a dimeric molecule (t-C4H9O)3SiS2Cd2 with a central four-membered Cd2S2 ring. According to the mass spectra the dimeric molecule is not preserved in the vapour phase. The compound is also characterized by 1H, 13C, 29Si NMR and UV spectra. Reactions with 1,10-phenanthroline and 2,2′-bipyridine afforded adducts with formal (RS)2,Cd(NN) stoichiometry. The central Cd2S2 kernel is folded with an angle of 150.6° at the CdCd diagonal. The cadmium atoms are three-fold bonded to thiolate sulphur atoms and the plane coordination is Cd(μ-SR)2(SR) with the mean distances of d(Cdμ-S) 256.0 pm and d(CdS) 240.8 pm. Additionally, there are weaker interactions with two oxygen atoms of two different tri-tert-butoxysilanethiolate ligands [d(CdO) 268 and 289 pm]. The comparison with the corresponding lead compound clearly shows the influence of the stereochemically active lone electron pair at lead(II).

Zinc silanethiolates: synthesis and properties. Crystal structures of bis(tri-tert-butoxysilanethiolato)(acetonitrile)zinc(II) and bis(tri-tert-butoxysilanethiolato)(bipyridine)zinc(II)

Abstract Reactions of tri- tert -butoxysilanethiol with inorganic zinc compounds such as [Zn(H 2 O) 4 ] 2+ , [Zn(NH 3 ) 4 ] 2+ , basic zinc carbonate, ZnCl 2 or with metallic zinc in water, benzene, or in the absence of solvent are described. Heteroleptic zinc silanethiolates such as {[( t BuO) 3 SiS] 2 Zn(H 2 O) n } m , and {[( t BuO) 3 SiS] 2 Zn(NH 3 )} 2 have been obtained. In acetonitrile as solvent [( t BuO) 3 SiS] 2 Zn(NCMe) is formed. All three of these new complexes reacted with the strong nitrogen donor species pyridine, 1-methylimidazole, 2,2′-bipyridine and 1,10-phenanthroline to give complexes of formula [( t BuO) 3 SiS] 2 ZnL 2 (L = py, l-meimid or L 2 = bipy, phen). Some reactions leading to cadmium complexes were also performed. The crystal structures of two compounds were determined. Orthorhombic crystals of [( t BuO) 3 SiS] 2 Zn(NCMe) consist of molecules in which the zinc atom is bonded to two sulphur atoms, two oxygen atoms and one nitrogen atom in a distorted trigonal bipyramidal arrangement. In the triclinic crystals [( t BuO) 3 SiS] 2 Zn(bipy) there is a ZnN 2 S 2 core with distorted tetrahedral geometry.

Contributions to the chemistry of silicon–sulfur compounds. Part 75. Cobalt(II) tri-tert-butoxysilanethiolates. Synthesis, properties, crystal and molecular structures of [Co{SSi(OtBu)3}2(L)] and [Co{SSi(OtBu)3}2(L)2] type complexes with monodentate nitrogen ligands

Abstract The title heteroleptic neutral cobalt(II) tri-tert-butoxysilanethiolate complexes with monodentate nitrogen bases (L) as additional ligands have been prepared by the reactions of [Co{μ-SSi(OtBu)3}{SSi(OtBu)3}(NH3)]2 (1) with respective bases. For pyridine both types have been prepared — with two (2) or one (3) nitrogen ligand bonded to cobalt(II). [Co{SSi(OtBu)3}2(L)] complexes have been obtained also with 2-picoline (5), 2,4-lutidine (6), 3,5-lutidine (7), and [Co{SSi(OtBu)3}2(L)2] also with N-methylimidazole (8) and morpholine (9). Molecular and crystal structures of the six compounds have been determined by single-crystal X-ray structural analysis. In 3, 5 and 7 three-coordinated cobalt(II) seems to interact very weakly with two oxygen atoms from two Si(OtBu)3 moieties approaching highly distorted trigonal bipyramidal geometry. Compounds 2, 8 and 9 have distorted tetrahedral structures. Both types of complexes gave characteristic electronic spectra, similar within each type.

The degree of σ-bond delocalization in polysilanes and its influence on reactivity by through-bond interactions the PES scaled Sandorfy C approach

Abstract The degree of σ-orbital delocalization m for alkanes and polysilanes was determined on the basis of the Sandorfy C quantum chemical model and PES

Cobalt(II) and Cobalt(III) Tri-tert-butoxysilanethiolates. Synthesis, Properties, Crystal and Molecular Structures of [Co{μ-SSi(OBut)3}{SSi(OBut)3}(NH3)]2 and [Co{SSi(OBut)3}2(NH3)4][SSi(OBut)3] Complexes

The heteroleptic neutral tri-tert-butoxysilanethiolate of cobalt(II) incorporating ammonia as additional ligand (1) has been prepared by the reaction of a cobalt(II) ammine complex with tri-tert-butoxysilanethiol in water. Complex 1, dissolved in hexane, undergoes oxidation in an ammonia saturated atmosphere to the ionic cobalt(III) compound 2. Molecular and crystal structures of 1 and 2 have been determined by single crystal X-ray structural analysis. 1 forms a dimeric molecule [Co{μ-SSi(OBut)3}{SSi(OBut)3}(NH3)]2 with a folded central Co2S2 ring and distorted tetrahedral ligand arrangement at both CoII atoms (CoNS3 core). The product 2 is composed of the octahedral CoIII complex cation [Co{SSi(OBut)3}2(NH3)4]+ and the tri-tert-butoxysilanethiolate anion. Within the crystal two pairs of ions interact by hydrogen bonds forming well separated entities. 1 and 2 are the first structurally characterized cobalt thiolates where metal is also bonded to ammonia and 2 is the first cobalt(III) silanethiolate. Beitrage zur Chemie der Silicium-Schwefel Verbindungen. 74. Cobalt(II) und Cobalt(III) Tri-tert-butoxysilanthiolate. Darstellung, Eigenschaften, Kristall- und Molekulstrukturen von [Co{μ-SSi(OBut)3}{SSi(OBut)3}(NH3)]2 und [Co{SSi(OBut)3}2(NH3)4][SSi(OBut)3] Das heteroleptische, neutrale, als zusatzlichen Liganden Ammoniak enthaltende Cobalt(II)-tri-tert-butoxysilanthiolat (1) wurde bei der Umsetzung von Tri-tert-butoxysilanthiol mit einem Cobalt–Ammin-Komplex in wasseriger Losung erhalten. Verbindung 1, aufgelost in Hexan, oxidiert sich in einer mit Ammoniak gesattigen Atmosphare zum ionischen Cobalt(III)-Komplex 2. Die Molekul- und Kristallstrukturen von 1 und 2 wurden rontgenographisch bestimmt. 1 bildet ein dimeres Molekul [Co{μ-SSi(OBut)3}{SSi(OBut)3}(NH3)]2 mit einen gefaltenen Co2S2 Ring und einer fast tetraedrischen Anordnung der Liganden an beiden CoII-Atomen (CoNS3 Rumpf). 2 ist ionisch aufgebaut mit einem oktaedrischen CoIII-Kation [Co{SSi(OBut)3}2(NH3)4]+ und einem Tri-tert-butoxysilanthiolat-Anion. Im Kristall sind zwei Paare dieser Ionen durch Wasserstoffbrucken zu isolierten Einheiten gebunden. 1 und 2 sind die ersten strukturell charakterisierten Cobalt-Thiolate, in welchen Cobalt noch an Ammoniak gebunden ist. Verbindung 2 ist das erste Cobalt(III)-Silanthiolat.

Zinc(II) Tri-tert-butoxysilanethiolates. Synthesis, Properties, Crystal and Molecular Structures of [Zn{SSi(OBut)3}2(NH3)L] (L = 2-Picoline or 2,4-Lutidine) and [Zn{SSi(OBut)3}2(NH3)2] · MeCN Complexes

[Zn{SSi(OBut)3}2(NH3)]2 (1) reacts with 2-picoline or 2,4-lutidine (L) without elimination of ammonia giving stable monometallic complexes [Zn{SSi(OBut)3}2(NH3)L] (3 and 4), with two different nitrogen ligands bonded to the metal center. Reaction of (ButO)3SiSH with zinc di(acetylacetonate) in ammonia atmosphere leads to the complex with two ammine ligands [Zn{SSi(OBut)3}2(NH3)2] · MeCN (5). Molecular and crystal structures of 3, 4 and 5 have been determined by the single crystal X-ray structural analysis. All have distorted tetrahedral geometry. The presence of ammonia gives rise to hydrogen bonds, different in all three cases. 3, 4, and 5 are the first examples of structurally characterized ammine ligated zinc thiolates. Beitrage zur Chemie der Silicium–Schwefel Verbindungen. 76. Zink(II) Tri-tert-butoxysilanthiolate. Darstellung, Eigenschaften, Kristallund Molekulstrukturen von [Zn{SSi(OBut)3}2(NH3)L] (L = 2-Picolin oder 2,4-Lutidin) und [Zn{SSi(OBut)3}2(NH3)2] · MeCN [Zn{SSi(OBut)3}2(NH3)]2 (1) reagiert mit 2-Picolin oder 2,4-Lutidin (L) ohne Eliminierung von Ammoniak unter Bildung von stabilen monometallischen Komplexen [Zn{SSi(OBut)3}2(NH3)L] (3 und 4), mit zwei verschiedenen stickstoffhaltigen Liganden am Metall-Zentrum. Eine Umsetzung von (ButO)3SiSH mit Zink-Acetylacetonat in einer Atmosphare von Ammoniak ergab einen Komplex mit zwei Ammoniak-Liganden [Zn{SSi(OBut)3}2(NH3)2] · MeCN (5). Die Molekul- und Kristallstrukturen von 3, 4 und 5 wurden rontgenographisch bestimmt. Alle Verbindungen zeigen eine Abweichung von einer tetraedrischen Geometrie. Die Anwesenheit von Ammoniak fuhrt zu Wasserstoffbruckenbindungen die sich in alle drei Fallen unterscheiden. Verbindungen 3, 4 und 5 sind die ersten, strukturell charakterisierten Zink-Thiolate in welchen Zink noch an Ammoniak gebunden ist.

Zinc tri-tert-butoxysilanethiolates. Syntheses, properties and crystal and molecular structures of [Zn{μ-SSi(OBut)3}(acac)]2 and [{(ButO)3SiS}(H2O)2Zn{μ-SSi(OBut)3}Zn(acac){SSi(OBut)3}]

Abstract Heteroleptic, neutral tri-tert-butoxysilanethiolates of zinc, incorporating acetylacetonate (1) or acetylacetonate and water (2) as additional ligands, have been prepared by a reaction of zinc acetylacetonate with tri-tert-butoxysilanethiol in acetonitrile and characterized by IR, NMR and MS techniques. Crystal and molecular structures have been determined by single crystal X-ray structural analysis. Both are bimetallic with a distorted tetrahedral ligand arrangement at the zinc and ZnO2S2 core. Complexes 1 and 2 are the first structurally characterized thiolates where the metal is also bonded to acetylacetonate and 2 is the first neutral aqua-ligated zinc thiolate.

Contributions to the Chemistry of Silicon—Sulfur Compounds. XXVII. The Insertion of Sulfur into the Silicon—Hydrogen Bond of Arylsilanes. The Preparation of Arylsilanethiols and Aryldisilthianes

Abstract The reaction of arylhydrosilanes with sulfur has been studied. The influence of temperature, solvent, catalysts and reagents ratio were considered. The relative reaction rates of hydrosilanes have been evaluated and reaction mechanism discussed. This insertion yields silanethiols which after following condensation yield disilthianes.

Contributions to the chemistry of silicon-sulphur compounds—LXI. The first neutral monomeric copper(I) thiolate complex. Crystal and molecular structure of (1,10-phenanthroline)(tri-tert-butoxysilanethiolato) copper(I), [Cu{SSi(OC4H9-t)3}(phen)] ☆ ☆☆

Abstract The title compound [Cu{SSi(OC 4 H 9 - t ) 3 }(phen)] ( 1 ), the first monomeric neutral copper(I) thiolate complex was obtained by reaction of 1,10-phenanthroline with [( t -BuO) 3 SiSCu] 4 in benzene and its crystal structure determined. The copper atom is threefold coordinated to one sulphur atom and two nitrogen atoms in a nearly trigonal planar arrangement. The relevant bond distances and angles are CuN 203.1(2) and 210.8(3) pm, CuS 214.0(1) pm, SSi 208.6(1) pm, NCUN 80.9(1)°, NCuS 133.5(1)° and 144.6(1)°, and CuSSi 102.1(1)°.

Contributions to the chemistry of silicon-sulphur compounds: XLV. σ-Bond conjugation in silicon-sulphur catenates

Abstract The electronic spectra of some polysilanes and their CT complexes with TCNE have been determined for the series: α, ω-(RO)3SiS(SiMe2)nSSi(OR)3 (n = 2, 3, 4, 6) and α-(RO)3SiS(SiMe2)nMe (n = 2, 4; R = i-Pr, t-Bu). Additional data for some related compounds are also presented. The results are discussed in terms of σ-silicon-silicon and σ-silicon-sulphur bond conjugation.