η¹and η²complexes of λ³-1,2,4,6-thiatriazinyls with CpCr(CO)_x

Abstract

The title heterocyclic radicals coordinate to either 17e CpCr(CO)3 or 15e CpCr(CO)2 moieties as one-electron or as three-electron donors, respectively; in the former the bonding is via the perpendicular p orbital of the sulfur atom, while in the latter bonding is via p(pi) orbitals on both sulfur and nitrogen.

Metal-radical coordination complexes of thiazyl and selenazyl ligands

“…In addition to reporting the formation of η 2 π-complexes of the [Cr(Cp)(CO) 2 ] • fragment with DTDA radicals, Boeré and co-workers have explored the reaction of [Cr(Cp)(CO) 3 ] 2 with a series of TTA radicals [102,103]. Interestingly, A c c e p t e d M a n u s c r i p t two types of coordination complexes are observed.…”

“…Line drawing of the TTA radicals that form coordination complexes with Cr(Cp)(CO) x ; examples of the two types of π-complexes, η 1 and η 2 (CSD Refcodes: NEVFAW and NEVFEA)[102].…”

A tert-butyl/cyano substituted (1,2,3,5-dithiadiazolyl)benzene and η2 π complexes with CpCr(CO)2

“…50% yield of new complexes with g 2 coordination across S-S bonds, which crystallize in either exo (3a) or endo (3b) isomeric forms (Scheme 1) [1]. Reaction of two different 1,2,4,6-thiatriazinyls (4a,b) with the same organometallic radical likewise yielded new complexes with either g 1 , 5, or g 2 , 6, coordination across S@N bonds (Scheme 2) [2]. The novelty in all of these reactions is the suppression of oxidative addition which normally results from the reaction of unsaturated S-N bonds with low-valent transition metal complexes [3].…”

“…We have recently communicated the first bona fide p-complexes of unsaturated electron-rich C,N,S heterocyles [1,2]. The reaction of two different 1,2,3,5-dithiadiazolyls, 1, with the radical released from [CpCr(CO) 3 ] 2 , 2 (Cp = g 5 -C 5 H 5 ) led to synthesis in ca.…”

“…Thus, the resulting primary products, A, from dibenzothiazolyl disulfide [(C 6 H 4 )-NSCS] 2 [8], B, tetraalkylthiuram disulfanes (R 2 NC(S)S) 2 [9], C, tetraalkyldiphosphine disulfide [10], D and E, diphenyl dichalcogenide Ph 2 E 2 (X = S, Se, Te) [11], F, thiophosphorus compounds bis(diphenylthiophosphinyl)disulfane (Ph 2 P(S)S) 2 [12], or the analogous bis(thiophosphoryl)-disulfane [(RO) 2 P(S)S] 2 (R = i Pr) [13], are the inevitable consequence of the coupling of 2 and organic sulfur-or phosphorus-centered radicals, under conditions where thermally induced radical cleavage of E-E bonds occurs.…”