Diplatinum O Compounds

Only a few compounds with Pt(0)-Pt(0) bonds were reported since 2005, due to the fact that this low-valent metal - mettil bond with highly occupied antibonding orbitals is thermodynamically unfavorable. Thus, sterically demanding ligands are necessary to provide kinetical stabilization. 

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In 2005, low-valent group 13 ligands were used to stabilize a series of Group 10 bimetallic and multimetallic compounds [120]. The diplatinum(O) compounds 160-163 and the Pt(0)-Pt(0) bond lengths are listed in Figure 10.15. The structures of 160-163 were found to be fluxional in solution, and ligand exchange reactions were demonstrated to be viable. 

In the following work, monovalent Group 13 compound with f)-diketiminato scaffold (BDI) were reacted with M(0) precursor, where M is Pd or Pt [121]. For platinum, a series of diplatinum(O) compounds were obtained and characterized (Figure 10.16) (Table 10.11). 

Fig. 2. Schematic structures of compounds related to platinum blues . Diplatinum(II) species with HH (A-l) and HT (A-2) oriented amidate ligands, tetraplatinum(II) species (A-3), tetranuclear [Pt2 25]4 blues without (B-l) and with axial ligand (B-2), tetranuclear [Pt2 5]4 tans (C-l, C-2), and various types of diplatinum(III) species with HH (D-l, D-3) and HT (D-2) orientation of the bridging ligands. The amidate ligands are expressed with their N- and O-coordinating atoms only.

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