[cis-{η²-(Ph₃PAu)₂}Ph₃PCr(CO)₄]·THF, featuring the shortest known separation between two Au metal centres in a heteronuclear Au₂Mcluster

Abstract

The title compound, tetracarbonyl-1kappa(4)C-tris(triphenylphosphino)-1kappaP,2kappaP,3kappaP-triangulo-chromiumdigold(Au-Au)(2 Cr-Au) tetrahydrofuran solvate, [Au(2)Cr(C(18)H(15)P)(3)(CO)(4)].C(4)H(8)O, is a stable isolobal analogue of the extremely labile [(eta(2)-H(2))CrL(n-1)] molecular hydrogen complex (n = 6; L is a neutral ligand, e.g. CO or PPh(3)), and features the shortest known separation [2.6937 (2) A] between two Au atoms in a triangular heteronuclear metal-cluster framework.

Electrochemically Controlled Formation/Dissociation of Phosphonate‐Cavitand/Methylpyridinium Complexes

“…To date, apart in elemental gold,2 the zero oxidation state has been mentioned in mixed gold(0)/gold(I) complexes of the general formula [(LAu) n ] m + , m X − as exemplified by the classical [(Ph 3 PAu) 6 ] 2+ 2(BF 4 − )3a and [( t Bu 3 PAu) 4 ] 2+ 2(BF 4 − ),3b and the recently reported {[(NHC)Au] 3 } + (TfO) − complex 4. There are also a few examples of multinuclear mixed‐metal clusters,5 such as [ cis ‐η 2 ‐{(Ph 3 P)AuAu(PPh 3 )}Ph 3 PCr(CO) 4 ],6 in which the Au atom can be considered to have an oxidation state of zero. However, mononuclear (L n Au), binuclear (LAuAuL), and polynuclear [(LAu) n ] neutral complexes in which atoms of gold are coordinated end‐on by L ligands have never been isolated 7.…”

Isolierung neutraler mono‐ und dinuklearer Goldkomplexe von cyclischen Alkyl(amino)carbenen

“…B. [ cis‐ η 2 ‐{(Ph 3 P)Au‐Au(PPh 3 )}Ph 3 PCr(CO) 4 ],6 in denen dem Goldatom die Oxidationszahl 0 zugeschrieben werden kann. Einkernige [L n Au]‐, zweikernige [LAu‐AuL]‐ und mehrkernige [(LAu) n ]‐Neutralkomplexe, in denen die Goldatome “end on” an die Liganden L gebunden sind, wurden bisher hingegen nicht isoliert 7.…”

Theoretical Chemistry of Gold

“…The calculated MP2‐level Au Mulliken charges for these complexes were nearly zero, which suggests the Au atom has an oxidation state of zero (Au 0 ). Another approximate example of such an “H 2 ” species is the gold–indium compound of Gabbaï et al192 The observed AuAu distance of 269.4 pm in the {CrAu 2 } triangle of [ Cis ‐η 2 ‐(Ph 3 PAu) 2 Ph 3 PCr(CO) 4 ]⋅THF could be regarded as a side‐on bonded “H 2 ” species or as the shortest known aurophilic bond 193…”