Berry John F, Cotton F Albert, Ibragimov Sergey A, Murillo Carlos A, Wang Xiaoping
Department of Chemistry and Laboratory for Molecular Structure and Bonding, P.O. Box 30012, Texas A & M University, College Station, Texas 77842-3012, USA.
Inorg Chem. 2005 Aug 22;44(17):6129-37. doi: 10.1021/ic050876c.
Reactions of Pd3(OAc)6 with lithium salts of mononegative bidentate N,N-ligands, L, of various types, such as formamidinates, benzamidinates, triazinates, and guanidinates, were investigated in a search for ways to obtain Pd2(4+) compounds that could serve as precursors to paddlewheel complexes with a metal-metal bond and a Pd2(5+) core. It was found that the reactions are complex and that either square planar mononuclear or dinuclear species may be formed depending on the reaction conditions or the method of isolation. For Pd2L4 compounds, alpha and beta isomers were sometimes obtainable. In the alpha isomer, all N,N-ligands serve as bridges, whereas in the beta isomer, two ligands bridge the Pd2(4+) unit and each of the other two chelate to a metal atom. Electrochemistry shows that the paddlewheel compounds Pd2(TolNC(H)NTol)4, Pd2(PhNC(Ph)NPh)4, and Pd2(PhNC(Ph)NPh)3(OAc) and the orthometalated complex cis-Pd2[eta2-C6H4NC(Ph)N(H)Ph]2(mu-OAc)2 have reversible oxidation waves between 0.70 and 0.92 V vs Ag/AgCl, which makes them good candidates for chemical oxidation.
研究了Pd3(OAc)6与各种类型的单负二齿N,N-配体（L）的锂盐的反应，这些配体包括甲脒盐、苯甲脒盐、三嗪盐和胍盐，目的是寻找获得Pd2(4+)化合物的方法，这些化合物可作为具有金属-金属键和Pd2(5+)核心的桨轮配合物的前体。发现反应很复杂，根据反应条件或分离方法，可能会形成平面正方形单核或双核物种。对于Pd2L4化合物，有时可以得到α和β异构体。在α异构体中，所有N,N-配体都作为桥连配体，而在β异构体中，两个配体桥连Pd2(4+)单元，另外两个配体中的每一个与一个金属原子螯合。电化学研究表明，桨轮化合物Pd2(TolNC(H)NTol)4、Pd2(PhNC(Ph)NPh)4和Pd2(PhNC(Ph)NPh)3(OAc)以及邻位金属化配合物顺式-Pd2[η2-C6H4NC(Ph)N(H)Ph]2(μ-OAc)2在相对于Ag/AgCl为0.70至0.92 V之间具有可逆氧化波，这使其成为化学氧化的良好候选物。
