Cobalt tris(mercaptoimidazolyl)borate complexes: synthetic studies and the structure of the first cobaltaboratrane

Abstract

The paramagnetic complexes (TmtBu)CoX (X = Cl, Br, I) have been readily prepared and structurally characterized and provide a convenient entry into cobalt(II) tris(mercaptoimidazolyl)borate chemistry. A number of derivatives, including mononuclear triphenylphosphine adducts [(TmtBu)Co(PPh3)]X and dinuclear compounds [Co2(TmtBu)2X]Y, have been prepared in order to ascertain whether cobalt is a reliable surrogate for zinc in biological systems, particularly in sulfur-rich coordination environments. The structure of the first cobaltaboratrane is also reported.

Toward a comprehensive definition of oxidation state (IUPAC Technical Report)

“…This is by no means unique, and SO 2 adducts with, for example, Pt(PR 3 ) 2 (R = cyclohexyl, tert-butyl) [317] or [PtX(C 6 H 2 {CH 2 N(CH 3 ) 2 } 2 -2,6-R-4)] (R = OH, X = Cl; R = H, X = Cl, Br, I) [318] are considered to contain respectively Pt(0) and Pt(II). Their reversible binding of SO 2 is more in accord with these OS than with ionic approximation towards Pt +2 The first structural identification of a TM → B donor-acceptor bond in the [Ru(CO)(P(C 6 H 5 ) 3 ){B(mt) 3 }] (B(mt) 3 = tris(methimazolyl)borane) metallaboratrane by Hill [321] in 1999 has rekindled interest in the field, which has seen spectacular progress in the intervening years when similar complexes of Co [322], Ni [323], and others have been synthesized. The TM → Z-type ligand interactions can be divided into two main classes: supported and unsupported by donor buttresses, Fig.…”

Wechselwirkung zwischen d‐ und p‐Block‐Metallen: Synthese und Struktur von Platin‐Alan‐Addukten

“…[2] Neuere Arbeiten von Hill, [3] Parkin, [4] Bourissou [5] und Rabinovich [6] zeigten, dass eine Reihe von Lewis-basischen Übergangsmetallzentren Borankomplexe vom Typ [L n M À BR 3 ] [7] bildet, und durch experimentelle sowie theoretische Studien konnte die Natur der dativen Metall-Bor-Bindung aufgeklärt werden. Weiter wurde gezeigt, dass die Metallphosphanfragmente {M(PCy 3 )} (M = Pd, Pt) gegenüber einer Reihe von koordinierten Boryl- [8] und Borylen-Liganden [9] vielseitig als Metallbasen einsetzbar sind.…”

Crystal field arguments to explain the trans labilisation within transition metal–borane complexes

“…This has been shown in a large number of examples that have been reported over the past few years. The majority of compounds, which have been provided by Hill [2][3][4][5][6][7][8][9][10][11][12] and others [13][14][15][16][17][18][19][20][21], contain either the flexible scorpionate ligand, Tm [hydrotris(2-methyl-1-imidazolyl)borate] or similar derivatives (Fig. 2).…”