Synthesis, Characterization, and Optical Properties of Pentafluorophenyl Complexes with a Pt−Cd Bond

Novel bimetallic neutral [(C6F5)4PtCd(cyclen)] and [(C6F5)2(C⋮CPh)2PtCd(cyclen)] (1, 2)
and cationic [(C6F5)2(bzq)PtCd(cyclen)](ClO4) (3) pentafluorophenylplatinum(II)−cadmium(II) derivatives have been prepared by treatment of the adequate anionic starting precursors
[Pt(C6F5)2X2]n- (n = 2, X = C6F5, C⋮CPh; n = 1, X2 = bzq) with Cd(ClO4)2 and cyclen. X-ray
diffraction studies on complexes 1, 2, and 3 show that they are stabilized by a short Pt→Cd
donor acceptor bond and, additionally, in complex 2 the Cd center is also coordinated to the
Cα of one of the two alkynyl groups. In contrast, treatment of the binuclear compound [NBu4]2[Pt2(μ-Cl)2(C6F5)4] with [Cd(cyclen)(MeOH)2](ClO4)2 afforded the tetranuclear derivative [Pt(C6F5)2Cl(μ-Cl)Cd(cyclen)]2 (4) (X-ray), in which Pt and Cd atoms are connected by a μ3-Cl
bridging ligand, and the binuclear cadmium complex [Cd2(μ-Cl)2(cyclen)2](ClO4)2 (5) (X-ray),
in which two “Cd(cyclen)” fragments are bridged by two chlorine atoms. The photoluminescent
properties of complexes 1−3 have also been examined and compared with those of their
corresponding anionic parent compounds [NBu4]2[Pt(C6F5)4], [PMePh3]2[Pt(C6F5)2(C⋮CPh)2],
and [NBu4][Pt(C6F5)2(bzq)] (6).