Crystallographic and Spectroscopic Characterization of Tetrakis(μ-N,N-diarylformamidinato)dichlorodirhenium(III,III) Compounds

Bis-Adducts of Substituted Phenylethynyl on a Ru2(DMBA)4 Core: Effect of Donor/Acceptor Modifications

“…Dinuclear paddlewheel species continue to attract significant attention, due to the diversity in both metal centers and bridging ligands, as well as their interesting electrochemical, magnetic, and other properties. , Facile electron delocalizations between dinuclear units linked via a π-delocalized framework have been demonstrated by the laboratories of Cotton, Bursten and Chisholm, , and Ren, , revealing the possibility of realizing molecular electronic wires based on these paddlewheel species. , To achieve this goal, the ability to precisely control the electronic properties of paddlewheel species is crucial. Previously, substituent effects in paddlewheel species were explored in our laboratory on a series of M 2 ( D Ar F ) 4 compounds with M = Mo, Ni, Ru, Rh and D Ar F = diarylformamidinate. − Initial studies of Mo 2 and Ni 2 series revealed that there is a linear correlation between electrode potentials of metal-based redox processes and the Hammett constants (σ) of the phenyl substituent on D Ar F ligands, and both the optical and structural features were unaltered by the substituents. − Similar results were found for the series of Rh 2 ( D Ar F ) 4 compounds and Ru 2 ( D Ar F ) 4 compounds bearing either chloro or phenylethynyl axial ligands in our laboratory, − Re 2 ( D Ar F ) 4 Cl 2 and Cr 2 ( D Ar F ) 4 compounds in the laboratory of Eglin, , and Ru 2 (X-ap) 4 Cl compounds (X-ap = substituted 2-anilinopyridinates) in the laboratory of Bear and Kadish . It was concluded that the phenyl substitution of the bridging ligands imparts an inductive effect on the dinuclear core .…”

Expanding the Chemistry of Rhenium Metal–Metal Bonded Fluoro Complexes: Facile Preparation and Characterization of Paddlewheel Complexes

“…There are no chloro and bromo analogues of 2; the structural parameters were compared with those in Re 2 (ArNCHNAr) 4 Cl 2 (where Ar = CH 3 C 6 H 5 (2.2759(3) Å), 7 p-OMe (2.2777(3) Å), m-OMe (2.2765(6) Å), 3,4-Cl 2 (2.2783(4) Å), 3,5-Cl 2 , (2.2734(3) Å)). 13 In 2, the Re−Re′ bond distance (2.2575(2) Å) is ∼0.02 Å shorter than in Re 2 (ArNCHNAr) 4 Cl 2 (Ar = CH 3 C 6 H 5 (2.2759(3) Å), 7 p-OMe (2.2777(3) Å), m-OMe (2.2765(6) Å), 3,4-Cl 2 (2.2783(4) Å), 3,5-Cl 2 (2.2734(3) Å)). 13 The Re−Re distance of Re 2 (dpf) 4 F 2 (2) is longer than in Re 2 (hpp) 4 F 2 (1), and this elongation is well reflected by a stronger interaction of the axial fluoride ligand (Table 1).…”

“…13 In 2, the Re−Re′ bond distance (2.2575(2) Å) is ∼0.02 Å shorter than in Re 2 (ArNCHNAr) 4 Cl 2 (Ar = CH 3 C 6 H 5 (2.2759(3) Å), 7 p-OMe (2.2777(3) Å), m-OMe (2.2765(6) Å), 3,4-Cl 2 (2.2783(4) Å), 3,5-Cl 2 (2.2734(3) Å)). 13 The Re−Re distance of Re 2 (dpf) 4 F 2 (2) is longer than in Re 2 (hpp) 4 F 2 (1), and this elongation is well reflected by a stronger interaction of the axial fluoride ligand (Table 1). The Re−F ax bond length (i.e., 2.059(1) Å) is ∼0.1 Å shorter than in 1.…”

Tetrakis(μ-benzothiazole-2-thiolato)-1:2κ4N:S2;1:2κ4S2:N-dichloro-1κCl,2κCl-dirhenium(III)(Re—Re) dichloromethane solvate: a bridged complex with a long Re—Re quadruple bond

“…In each of these molecules, there is at least one bridging ligand. These bridging ligands are 2,6-bis(diphenylphosphino)pyridine (Cotton et al, 1998) and N,N H -diarylformamidinate, where aryl is p-tolyl (Cotton & Ren, 1992), and p-methoxyphenyl, 3,4-dichlorophenyl and 3,5-dichlorophenyl (Eglin et al, 1999). All torsion angles about the dirhenium units are less than 12 , but the ReÐRe bond distances range from 2.270 to 2.304 A Ê .…”