Chelating or bridging Pd(ii) and Pt(ii) metalloligands from the functional phosphine ligand N-(diphenylphosphino)-1,3,4-thiadiazol-2-amine. New heterometallic Pd(ii)/Pt(ii) and Pt(ii)/Au(i) complexes
作者:Shuanming Zhang、Roberto Pattacini、Pierre Braunstein
DOI:10.1039/c0dt01782e
日期:——
The reaction of two equivalents of the functional phosphine ligand N-(diphenylphosphino)-1,3,4-thiadiazol-2-amine Ph2PNHCNNCHS (2) with [PdCl2(NCPh)2] in the presence of NEt3 gives the neutral, P,N-chelated complex cis-[Pd(Ph2PNCNNCHS)2] ([Pd(2−H)2], 3b), which is analogous to the Pt(II) analoguecis-[Pt(Ph2PNCNNCHS)2] ([Pt(2−H)2], 3a) reported previously. These complexes function as chelating metalloligands when further coordinated to a metal through each of the CH-N atoms. In the resulting complexes, each endo-cyclic N donor of the thiadiazole rings is bonded to a different metal centre. Thus, the heterodinuclear palladium/platinum complexes cis-[Pt(Ph2PNCNNCHS)2PdCl2] ([Pt(2−H)2·PdCl2], 4a) and cis-[Pd(Ph2PNCNNCHS)2PtCl2] ([Pd(2−H)2·PtCl2], 4b) were obtained by reaction with [PdCl2(NCPh)2] and [PtCl2(NCPh)2], respectively. In contrast, reaction of 3a with [AuCl(tht)] occurred instead at the P-bound N atom, and afforded the platinum/digold complex cis-[PtPh2PN(AuCl)CNNCHS}2] ([Pt(2−H)2(AuCl)2], 5). For comparison, reaction of 4a with HBF4 yielded cis-[Pt(Ph2PNHCNNCHS)2PdCl2](BF4)2 ([H24a](BF4)2, 6), in which the chelated PdCl2 moiety is retained. Complexes 3b, 4a·CH2Cl2, 4b·0.5C7H8, 5·4CHCl3 and 6 have been structurally characterized by X-ray diffraction.
两当量的功能膦配体 N-(二苯基膦)-1,3,4-噻二唑-2-胺 Ph2PNHCNNCHS (2) 与 [PdCl2(NCPh)2] 在 NEt3 存在下反应,得到中性的 P, N-螯合复合物 cis-[Pd(Ph2PNCNNCHS)2] ([Pd(2−H)2], 3b),类似于 Pt(II) 类似物cis-[Pt(Ph2PNCNNCHS)2] ([Pt(2 -H)2], 3a) 先前报道过。当通过每个 CH-N 原子进一步与金属配位时,这些配合物起到螯合金属配体的作用。在所得配合物中,噻二唑环的每个内环N供体键合到不同的金属中心。因此,异双核钯/铂络合物 cis-[Pt(Ph2PNCNNCHS)2PdCl2] ([Pt(2−H)2·PdCl2], 4a) 和 cis-[Pd(Ph2PNCNNCHS)2PtCl2] ([Pd(2−H))分别与[PdCl2(NCPh)2]和[PtCl2(NCPh)2]反应得到2·PtCl2]、4b)。相反,3a 与 [AuCl(tht)] 的反应发生在 P 结合的 N 原子上,并得到铂/二金配合物 cis-[PtPh2PN(AuCl)CNNCHS}2] ([Pt(2−H) )2(AuCl)2], 5)。为了进行比较,4a 与 HBF4 反应生成顺式-[Pt(Ph2PNHCNNCHS)2PdCl2](BF4)2 ([H24a](BF4)2, 6),其中保留了螯合的 PdCl2 部分。配合物3b、4a·CH2Cl2、4b·0.5C7H8、5·4CHCl3 和6 已通过X 射线衍射进行了结构表征。