title: Synthesis and characterisation of neutral mononuclear cuprous complexes based on dipyrrin derivatives and phosphine mixed-ligands.
abstract: Heteroleptic neutral mononuclear cuprous complexes with dipyrrin derivatives and phosphine mixed-ligands including 1,3,7,9-tetramethyldipyrrin (1), 5-phenyl-1,3,7,9-tetramethyldipyrrin (2), 2,8-dibromo-1,3,7,9-tetramethyldipyrrin (3), 1,9-dichloro-5-phenyldipyrrin (4), 1,9-dibromo-5-phenyldipyrrin (5), 5-pentafluorophenyl-1,3,7,9-tetramethyldipyrrin (6) and 1,5,9-triphenyldipyrrin (7) have been synthesized and fully characterized. The central Cu(i) atoms of these complexes in general formulas of Cu(1-6)(PPh(3))(2) (1a-6a) and Cu(1-6)(DPEphos) (1b-6b) [DPEphos = bis(2-diphenylphosphinophenyl)ether] all exhibit a pseudo-tetrahedral geometry, while complex Cu(7)(PPh(3)) (7a) is tricoordinated in a pyramidal conformation due to the large steric hindrance of ligand 7. The oxidation potentials assigned to oxidations of Cu(i)-Cu(ii) are extraordinarily low in the range of 0.36-1.02 V vs. Ag/AgCl compared with traditional [Cu(phen)(PP)](+) analogues. Their emission maxima range from 495 to 595 nm in dichloromethane at room temperature with quantum yields of 0.05-4.03% and lifetimes on the order of nanoseconds. Unlike the characteristic MLCT emission in cationic Cu(i) complexes, the emissions are assigned to the dipyrrin-centered intraligand charge transition (ILCT) based on the fact that the increased conjugation within the dipyrrinato anion leads to a weaker metal-ligand interaction, thus preventing the mixing of π orbitals of ligand and 3d orbitals of Cu(i) atom. This conclusion is also supported by electrochemical data and theoretical calculations.
authors: State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
authors: Xiaohui
authors: X
authors: Liu
authors: Hongmei
authors: H
authors: Nan
authors: Wei
authors: W
authors: Sun
authors: Qikai
authors: Q
authors: Zhang
authors: Mingjian
authors: M
authors: Zhan
authors: Luyi
authors: L
authors: Zou
authors: Zhiyuan
authors: Z
authors: Xie
authors: Xiao
authors: X
authors: Li
authors: Canzhong
authors: C
authors: Lu
authors: Yanxiang
authors: Y
authors: Cheng
mesh_terms: D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008024:Ligands; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010720:Phosphines / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D056831:Coordination Complexes; D008024:Ligands; D010720:Phosphines; D011758:Pyrroles; D003300:Copper; C044646:phosphine