Free and coordinated biarsolyls

Abstract

A trace side product from the reaction of [Mo(AsC4Me4)(CO)3(η5-C5H5)] with [Mn(THF)(CO)2(η5-C5H4Me)] was identified as the biarsolyl complex [Mn2{μ-(AsC4Me4)2}(CO)4(η5-C5H4Me)2] on the basis of a strategic synthesis from [Mn(THF)(CO)2(η5-C5H4Me)] and the pre-formed...

σ-Arsolido complexes

“…The outcome was reproducible and proved to be a reliable (albeit atom-inefficient and modest yielding) method for synthesising 2,2′,3,3′,4,4′,5,5′-octaphenylbisarsole which was until recently unknown, when it first appeared in a study of biarsolyl bridging ligands that included its crystallographic analysis. 18…”

“…Theopold has the developed the synthesis of As-chlorotetramethylarsole 19 via a Fagan–Nugent zirconole protocol 20 that may be simplified to a single ‘pot’ procedure by employing Negishi's dibutylzirconocene in situ . 18,20 b Mixing one equivalent each of freshly-prepared ClAsC 4 Me 4 and 4b in n -hexane results in the immediate formation of a deep orange solution that provides the expected [Mo(AsC 4 Me 4 )(CO) 3 (η 5 -C 5 H 5 )] ( 2c ) in acceptable yields after anaerobic chromatography (Scheme 7). Initial experiments required two iterations of this time-consuming process to separate 2c from oily tin-containing residues.…”

“…In the absence of computation data for simple X-type σ-arsolyls, 5,18 the complexes [Mo(AsMe 2 )(CO) 3 (η 5 -C 5 H 5 )], 45 [Mo{As(CHCH 2 ) 2 }(CO) 3 (η 5 -C 5 H 5 )] (unknown) and [Mo(σ-AsC 4 R 4 )(CO) 3 (η 5 -C 5 H 5 )] (R = H, Me 2d , Ph 2b ) were considered so as to assess the impact of introducing unsaturation in the arsenic substituents and then steric bulk. Optimised geometries for these complexes are displayed in Fig.…”

“…Thus while remaining elusive, the obtention of trigonally 3-valence electron (XL) arsolyl ligands would appear viable, the only caveat being the demonstrated propensity of σ-arsolyls to react with coordinatively unsaturated metal centres to adopt bridging roles. 1,2 d ,5,18…”

Poly(imidazolyliden-yl)borato Complexes of Tungsten: Mapping Steric vs. Electronic Features of Facially Coordinating Ligands

“…Carbynes ligated by the heavier pnictolyl ligands η 5 -AC 4 R 4 (A = P, As), however, remain unknown, though both ligands have been shown to serve as ersatz cyclopentadienyls [137][138][139][140]. With the ready availability of synthetic routes to anionic pnictolyl reagents, it may be presumed that complexes of the form [M(≡CR)(CO) 2 (η 5 -AC 4 R' 4 )] (A = P, As, Sb) will emerge in the future, given that, like carbynes, arsolyl ligands have been shown to support intermetallic bonding [141][142][143].…”