Preparation and structure of dichlorotetrakis(o-oxypyridine)dirhenium(III)

Difluorotetrakis(2‐oxypyridine)dirhenium(III) – Preparation, Crystallographic Structure, and Electrochemical Properties

“…The nitrogen atoms on the same rhenium atom are cis to each other and a similar motif is observed with Re 2 (2‐Opy) 4 Cl 2 . [3a] The Re–Re bond length in 1 , 2.2091(7) Å, is slightly longer (0.003 Å) than its chloro derivative (Table ). The Re–Re bond in Re 2 (2‐Opy) 4 F 2 is 0.02 Å longer than Re 2 (hpp) 4 F 2 and 0.04 Å shorter than Re 2 (dpf) 4 F 2 .…”

“…The metal–metal bond chemistry of group 6–8 transition metal complexes containing pyridine derivatives is well developed. Quadruply bonded complexes with pyridine‐type ligands (Scheme ) usually exhibit the stoichiometry M 2 L 4 , M 2 L 4 X or M 2 L 2 X 2 , ( M = Cr, Mo, W, Tc, Re, Os, Ru) [HL = 2‐hydroxypyridine (2‐HOpy), 2‐methyl‐6‐hydroxypyridine (Hmhp), 2,4‐dimethyl‐6‐hydroxypyridine (Hdmhp), 6‐chloro‐2‐hydroxypyridine (chp)]. Cotton and Gage first reported Re 2 (2‐Opy) 4 Cl 2 , which was obtained from the reaction ( n Bu 4 N) 2 [Re 2 X 8 ] with molten 2‐hydroxypyridine in an inert atmosphere.…”

“…Cotton and Gage first reported Re 2 (2‐Opy) 4 Cl 2 , which was obtained from the reaction ( n Bu 4 N) 2 [Re 2 X 8 ] with molten 2‐hydroxypyridine in an inert atmosphere. [3a] Later, Walton , et al reported the high yield preparation of Re 2 (2‐Opy) 4 X 2 ( X = Cl, Br, I) through the reaction of ( n Bu 4 N) 2 [Re 2 X 8 ] with 2‐hydroxypyridine in refluxing n ‐pentanol. [3b] In addition, the paramagnetic anions, [Re 2 (2‐Opy) 4 X 2 ] – , were isolated using cobaltocene as a one‐electron reducing agent.…”

“…[3a] Later, Walton , et al reported the high yield preparation of Re 2 (2‐Opy) 4 X 2 ( X = Cl, Br, I) through the reaction of ( n Bu 4 N) 2 [Re 2 X 8 ] with 2‐hydroxypyridine in refluxing n ‐pentanol. [3b] In addition, the paramagnetic anions, [Re 2 (2‐Opy) 4 X 2 ] – , were isolated using cobaltocene as a one‐electron reducing agent. In 1988, Walton and co‐workers reported the complexes Re 2 (2‐Opy) 4 Cl 2 · 2‐HOPy, and Re 2 (mhp) 2 Cl 4 from the reactions of Re 2 (O 2 C R ) 2 X 4 with 2‐HOPy and Hmhp, respectively …”

“…Rhenium complexes with the stoichiometry Re 2 L 4 Cl 2 can be prepared by the solid‐state‐melt reaction (SSMR) technique using protonated HL ligand (L: hpp = hexahydro‐2H‐pyrimibis[1,2a]pyrimidinate; dtf = ditolylformamidinate; Opy = 2‐oxypyridinate). [3a], Recently, we reported the high yield preparation of (NH 4 ) 2 [Re 2 F 8 ] · 2H 2 O as well as Re 2 (hpp) 4 F 2 , Re 2 (dpf) 4 F 2 , and [Re 2 (hpp) 4 F 2 ](PF 6 ) . (NH 4 ) 2 [Re 2 F 8 ] · 2H 2 O was obtained from the SSMR of ( n Bu 4 N) 2 [Re 2 Cl 8 ] with molten ammonium bifluoride,[8a] whereas the other complexes were obtained from the reaction of (NH 4 ) 2 [Re 2 F 8 ] · 2H 2 O with the molten ligand.…”