Synthesis, Structure, and Luminescence of Di- and Trinuclear Palladium/Gold and Platinum/Gold Complexes with (2,7-Di-<i>tert</i>-butylfluoren-9-ylidene)methanedithiolate^†^,1

Acetone solutions of [Au(OClO3)(PCy3)] react with complexes [M{S2C=(t-Bu-fy)}2]2- [t-Bu-fy = 2,7-di-tert-butylfluoren-9-ylidene; M = Pd (2a), Pt (2b)] or [M{S2C=(t-Bu-fy)}(dbbpy)] [dbbpy = 4,4‘-di-tert-butyl-2,2‘-bipyridyl; M = Pd (3a), Pt (3b)] to give the heteronuclear complexes [M{S2C=(t-Bu-fy)}2{Au(PCy3)}2] [2:1 molar ratio; M = Pd (4a), Pt (4b)], [M{S2C=(t-Bu-fy)}(dbbpy){Au(PCy3)}]ClO4 [1:1 molar ratio; M = Pd (5a), Pt (5b)], or [M{S2C=(t-Bu-fy)}(dbbpy){Au(PCy3)}2](ClO4)2 [2:1 molar ratio; M = Pd (6a), Pt (6b)]. The crystal structures of 3a, 4a, 4b, 5b, and 6a have been solved by single-crystal X-ray studies and, in the cases of the heteronuclear derivatives, reveal the formation of short Pd···Au or Pt···Au metallophilic contacts in the range of 3.048−3.311 Å. Compounds 4a and b and 5a and b undergo a dynamic process in solution that involves the migration of the [Au(PCy3)]+ units between the sulfur atoms of the dithiolato ligands. The coordination of 2a and b and 3a and b to [Au(PCy3)]+ units results in important modifications of their photophysical properties. The dominant effect in the absorption spectra is an increase in the energy of the MLCT (4a and b) or charge transfer to diimine (5a, b, 6a, b) transitions because of a decrease in the energies of the mixed metal/dithiolate HOMOs. The Pd complexes 2a and 4a are luminescent at 77 K, and the features of their emissions are consistent with an essentially metal-centered 3d−d state. The Pt/Au complexes are also luminescent at 77 K, and their emissions can be assigned as originating from a MLCT triplet state (4b) or a mixture of charge transfer to diimine and diimine intraligand π−π* triplet states (5b and 6b).将[Au(OClO₃)(三环己基膦（PCy3）)]的丙酮溶液，与配合物[M{S₂C=(t-Bu-fy)}₂]²⁻ [其中t-Bu-fy为2,7-二叔丁基芴-9-亚基（2,7-di-tert-butylfluoren-9-ylidene），M为Pd、Pt，对应配合物记为2a、2b]，或配合物[M{S₂C=(t-Bu-fy)}(dbbpy)] [其中dbbpy为4,4'-二叔丁基-2,2'-联吡啶（4,4‘-di-tert-butyl-2,2‘-bipyridyl），M为Pd、Pt，对应配合物记为3a、3b]发生反应，可得到三类异核配合物：摩尔比为2:1的[M{S₂C=(t-Bu-fy)}₂{Au(PCy3)}₂]（M=Pd为4a、Pt为4b）、摩尔比为1:1的[M{S₂C=(t-Bu-fy)}(dbbpy){Au(PCy3)}]ClO₄（M=Pd为5a、Pt为5b），以及摩尔比为2:1的[M{S₂C=(t-Bu-fy)}(dbbpy){Au(PCy3)}₂](ClO₄)₂（M=Pd为6a、Pt为6b）。通过单晶X射线衍射研究解析了3a、4a、4b、5b及6a的晶体结构，针对上述异核衍生物的结构分析显示，其存在Pd···Au或Pt···Au的短程亲金属接触，作用距离介于3.048~3.311 Å之间。化合物4a、4b与5a、5b在溶液中存在动态过程，该过程涉及[Au(PCy3)]⁺单元在二硫代配体的硫原子之间发生迁移。将2a、2b及3a、3b与[Au(PCy3)]⁺单元配位后，其光物理性质会发生显著改变；吸收光谱中的主导效应为：金属到配体电荷转移（Metal-to-Ligand Charge Transfer，MLCT）跃迁（对应4a、4b）或电荷转移至二亚胺配体的跃迁（对应5a、5b、6a、6b）的能量升高，这源于混合金属/二硫代配体的最高占据分子轨道（Highest Occupied Molecular Orbital，HOMO）能量降低。钯基配合物2a和4a在77 K下具有发光特性，其发射光谱特征与以金属为中心的3d−d跃迁态基本一致；铂/金类配合物同样在77 K下发光，其发射可分别归因为源自MLCT三重态（4b），或电荷转移至二亚胺配体与二亚胺配体内π−π*三重态的混合态（5b和6b）。