Facile Synthesis and Ambident Coordination of Cyclohexylbis(2‐pyridyl)phosphane: Novel Dinuclear Complexes of Cu +1 , Ag +1 , and Co +2 Ions

The title compound cyclohexylbis(2‐pyridyl)phosphane ( 1 ) was synthesized by a Pd 0 ‐catalyzed cross‐coupling reaction from 2‐bromopyridine and cyclohexylphosphane in 98% yield. Compound 1 formed colorless crystals that were moderately air‐stable. It reacted, in CH 3 CN, with CuOTf (OTf = OSO 2 CF 3 ), AgBF 4 , and Co(BF 4 ) 2 to form the complexes [Cu 2 {CyP(2‐Py) 2 } 2 (NCCH 3 ) 2 ](OTf) 2 ( 2 ), [Ag 2 {CyP(2‐Py) 2 } 2 (NCCH 3 ) 2 ](BF 4 ) 2 ( 3 ), and [Co 2 {CyP(2‐Py) 2 } 2 (NCCH 3 ) 2 ](BF 4 ) 4 ( 4 ), respectively. In these complexes, the pyridylphosphane ligands coordinate to two metal centers in a head‐to‐tail fashion involving both the P and the N atoms simultaneously. The compounds represent the first structurally characterized examples of dimeric dinuclear pyridylphosphane complexes showing the P , N , N ′ coordination. Reactions of 1 with other salts containing Cu +1 and Co +2 centers and coordinating anions resulted in different coordination modes. Thus, CuI reacted with 1 to form the complex [Cu 2 {CyP(2‐Py) 2 } 2 I 2 ] ( 5 ) with both coordinated P and N donor centers and a terminal iodide. In contrast, the reaction of 1 with CoCl 2 afforded the mononuclear complex [Co{CyP(2‐Py) 2 }Cl 2 }] ( 6 ) in which only the pyridyl N atoms and the chlorine ligands were coordinated to the metal center. X‐ray analyses of the compounds 1 , 2 , 3 , 5 , and 6 are reported.