The crystal structure of SeOCl₂.2C₅H₅N

Abstract

The crystal structure of the addition compound SeOCI~. 2 CsHsN has been determined and refined using three-dimensional X-ray data. There are two molecules in the triclinic unit cell with the constants a ----8. The nature of the chemical bonds and the problem of chloride-ion transfer processes in solutions of pyridine in selenium oxychloride are brieily discussed.

The structure of dichlorobis-(2-methylpyridine)copper(II). A five-coordinate copper complex

“…An interesting comparison can be made between the structure of dichlorobis-(2-methylpyridine)copper(II) and that of SeOCl2(pyridine)/. This structure also consists of dimeric units in which the centrosymmetrically related molecules are held together by weak Se... C1 bridges (Lindquist & Nahringbauer, 1959). The selenium atom in this structure has a tetragonal pyramidal environment with the oxygen at the apex of the pyramid and a trans arrangement of nitrogen and chlorine atoms in the basal plane.…”

Bariumhexaoxoditellurat(IV,VI): Sauerstoffkoordinationszahl fünf am vierwertigen Tellur

“…z.B. 1,848 (4) bis 1,972 (4)/~, in Te20 5 (Lindqvist & Moret, 1973), 1,903 (8) bis 1,948 (9) A in Te409 (Lindqvist, Mark & Moret, 1975).…”

Donor−Acceptor Chemistry at Heavy Chalcogen Centers

“…Examples of such bonding environments have been identified over the past five decades featuring SfSe, NfSe, SfTe, OfTe, PfSe, and recently NfTe coordination, indicating that the isolation of such compounds is achievable. 9,12, [38][39][40][41][42][43][44][45] In addition, the chalcogen atom transfer from one organophosphine to a more basic organophosphine (R 3 P ) Ch to R′ 3 P ) Ch), could be described as a ligand exchange indicative of the coordinative bond, yet this is restricted to Ch-P bond formationonly,withnofunctionalityontheheavychalcogen. 46,47 The 1:1 stoichiometric reaction between organophosphine (R 3 P; R ) Et, n Bu, Cy, Ph) and [3][GaCl 4 ] in CH 2 Cl 2 immediately results in the formation of clear, colorless solutions.…”

“…Numerous Ch(II) synthons play important roles in coordination chemistry as ligands on transition metals or as main group Lewis acids. − Given the electron rich (“lone pair” bearing) nature of these elements, this may not be surprising; however, many Ch(II) starting materials are used in a variety of organic transformations because of their inherent electrophilicity and electropositive nature. − In this context, it is remarkable that the acceptor capabilities of these elements have not been thoroughly harnessed for the formation of E→Ch coordination complexes. Examples of such bonding environments have been identified over the past five decades featuring S→Se, N→Se, S→Te, O→Te, P→Se, and recently N→Te coordination, indicating that the isolation of such compounds is achievable. ,,− In addition, the chalcogen atom transfer from one organophosphine to a more basic organophosphine (R 3 P = Ch to R′ 3 P = Ch), could be described as a ligand exchange indicative of the coordinative bond, yet this is restricted to Ch-P bond formation only, with no functionality on the heavy chalcogen. , …”