Synthesis, Structures and Magnetic Properties of Two Binuclear Cobalt(II) Complexes Bridged by Bis( p ‐nitrophenyl) Phosphate or Diphenylphosphinate Ion

Two new binuclear cobalt(II) complexes, [Co 2 L 1 ( μ 2 ‐DPP)] 2+ ( 1 ) (H L 1 = N , N , N ′, N ′‐ tetrakis (2‐benzimidazolylmethyl)‐2‐hydroxyl ‐1,3‐diaminopropane; DPP = diphenylphosphinate) and [Co 2 L 2 ( μ 2 ‐BNPP) 2 ] + ( 2 ) (H L 2 = 2,6‐bis‐[N,N‐di(2‐ pyridylmethyl)aminomethyl]‐4‐methylphenol, BNPP = bis(4‐nitrophenyl)phosphate) have been synthesized and their crystal structures and magnetic properties are shown. In 1 , each Co II atom has a distorted trigonal bipyramidal coordination sphere with a N 3 O 2 donor set and the central two Co II atoms are bridged by one alkoxo‐O atom and one μ 2 ‐DPP ion with the Co1‐Co2 separation of 3.542Å. In 2 , each Co II atom has a pseudo octahedral environment with a N 3 O 3 donor set and the central two Co II atoms are bridged by a phenolic oxygen atom of L 2 and two μ 2 ‐BNPP ions with the Co1‐Co2 separation of 3.667Å. Susceptibility data of 1 and 2 indicate intramolecular antiferromagnetic coupling of the high‐spin Co II atoms.