Molecular structures of pyridinethiolato complexes of Sn(II), Sn(IV), Ge(IV), and Si(IV)

Abstract

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.

On Two Solvate Crystals of Di‐μ‐sulfido(‐dithiocarbamate)‐tin­(IV): [Sn(S2CNH2)2S]2·2H2O·EtOH and [Sn(S2CNH2)2S]2·­4EtOH

“…The corresponding distances Sn-S are in the range of 2.4572(9) to 2.5904(8) Å, ( [13] and [SnS(PyS) 2 ] 2 ·THF. [14] The geometric parameters inside the four-membered rings closely follow those reported in this work as well. The sum of the four angles at tin and sulfur always equals 360°, as needed for a planar rectangle.…”

The First Structurally Characterised Example of Silicon in an S6 Coordination Sphere

“…Higher coordination numbers involving mixed donor sets including sulfur are rare. Amongst these, however, are species based on amine‐thiones which are the precursors of the ligand system discussed here . Indeed, the silylene compounds reported by Wagler et al could be described as inverse scorpionates or silatranes.…”

“…Few structurally characterised sulfur donor adducts of silicon are known, but the mono‐ and bis‐thiolates adopt a simple S 4 tetrahedral motif . However, a number of structures and reports have appeared which suggest that under certain circumstances the coordination number at silicon centres containing sulfur donor atoms can rise to six, although no species with S 6 ‐donor sets are known . Among these six coordinate species are the halo‐silylene adducts of methimazole which are reminiscent of our scorpionate compounds .…”

“…However, a number of structures and reports have appeared which suggest that under certain circumstances the coordination number at silicon centres containing sulfur donor atoms can rise to six, although no species with S 6 ‐donor sets are known . Among these six coordinate species are the halo‐silylene adducts of methimazole which are reminiscent of our scorpionate compounds . These observations, coupled with our general interest in the group 14 adducts of hydrotris(methimazolyl)borate anion, encouraged us to explore the reaction of Tm R with silicon tetraiodide …”

(2-Pyridyloxy)silanes as Ligands in Transition Metal Coordination Chemistry

“…In both of the compounds, the Si atom is essentially tetracoordinate and the coordination sphere may be described as (4 + 3) in MeSi(pyO)3 and (4 + 4) in Si(pyO)4, because of the pyridine N atoms, which are capping the faces of the tetrahedral coordination spheres from distances close to the sum of the van-der-Waals radii (ranging between 2.91 and 3.03 Å). This tetracoordination of Si in Si(pyO)4 is in contrast to the Si hexacoordination in the thio analog Si(pyS)4 [27] (and other pyS-bearing Si compounds [28]), in which two of the 2-mercaptopyridyl ligands form four-membered chelates, and in complexes of the N-oxide of the pyO system, which forms five-membered chelates [29,30].…”