Bortoluzzi M, Cesari C, Ciabatti I, Femoni C, Iapalucci MC, Zacchini S. Reactions of Platinum Carbonyl Chini Clusters with Ag(NHC)Cl Complexes: Formation of Acid-Base Lewis Adducts and Heteroleptic Clusters.
Inorg Chem 2017;
56:6532-6544. [PMID:
28489358 DOI:
10.1021/acs.inorgchem.7b00665]
[Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reactions of anionic platinum carbonyl Chini clusters [Pt3n(CO)6n]2- [n = 2 (1), 3 (2), 4 (3)] with Ag(IPr)Cl [IPr = C3N2H2(C6H3iPr2)2] afford the neutral acid-base Lewis adducts [Pt9(CO)18(AgIPr)2] (4) and [Pt6(CO)12(AgIPr)2] (5). These are thermally transformed into the homometallic heteroleptic neutral cluster [Pt3(CO)4(IPr)2] (6). Alternatively, 6 can be obtained from the reactions of 1-3 with an excess of the free IPr carbene ligand. The formation of 6 is sometimes accompanied by trace amounts of [Pt4(CO)4(IPr)3] (7). The reaction of 6 with free IPr affords the closely related [Pt3(CO)3(IPr)3] (8) heteroleptic cluster by substitution of the unique terminal CO ligand with a third IPr ligand. The reactions of 1-3 with Ag(IMes)Cl [IMes = C3N2H2(C6H2Me3)2] proceed differently from those involving Ag(IPr)Cl. Indeed, the only product isolated after workup is the bimetallic tetranuclear cluster [Pt3(CO)3(IMes)3(AgCl)] (9). 9 slowly reacts under a CO atmosphere, resulting in the pentanuclear [Pt5(CO)7(IMes)3] (10) complex. All of the new clusters 4-10 have been spectroscopically characterized and their molecular structures determined by X-ray crystallography. 4 and 5 retain the original trigonal-prismatic structures of the parent anionic Chini clusters, which are capped by two [Ag(IPr)]+ moieties. Conversely, 6-9 are based on a Pt3 triangular core decorated by CO and N-heterocyclic carbene ligands as well as Pt(CO) (in the case of 7) and AgCl (9) moieties. 10 displays an edge-bridged tetrahedral geometry.
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