Dinuclear cyclometallated complexes of Pd II with diphosphines. X-ray crystal structure of [formula omitted

Abstract

Treatment of the cyclometallated halide-bridged complexes [1,4-{ Pd[2,3,4-( MeO) 3 C 6 HC(H) = N]( X)} 2 C 6 H 4] 2 ( 1a, 2a), [1,4-{ Pd[2,4-( MeO) 2 C 6 H 2 C(H)= N ]( X)} 2 C 6 H 4] 2 ( 1b, 2b), [1,4-{ Pd[3-( Me-4- MeOC 6 H 2 C(H)= N ]( X)} 2 C 6 H 4] 2 ( 1c, 2c), [1,4-{ Pd[4,5-( OCH 2 O)C 6 H 2 C(H)= N]( X)} 2 C 6 H 4] 2 ( 1d, 2d), (X = Cl, Br) with ditertiary diphosphines in a complex/diphosphine 1:4 molar ratio and ammonium hexafluorophosphate gave the dinuclear cyclometallated complexes [1,4-{ Pd[2,3,4-(MeO) 3C 6HC(H)N ]} 2C 6H 4(LL) 2][PF 6] 2[LL  Ph 2PCH(CH) 3)PPh 2, Ph 2P(CH 2) 2PPh 2 , 3a, 4a], [1,4-{ Pd[2,4-( MeO) 2 C 6 H 2 C(H)= N ]} 2 C 6 H 4( LL) 2][ PF 6] 2[LL  Ph 2 PCH(CH 3) PPh 2, Ph 2 P(CH 2) 2 PPh 2 , 3b, 4b] [1,4-{ Pd[3-( Me-4- MeOC 6 H 2 C(H)= N ]} C 6 H 4( LL) 2][ PF 6] 2[LL  Ph 2 PCH(CH 3) PPh 2, Ph 2 P(CH 2) n PPh 2, n = 2, 3 , 3c, 4c, 5c], [1,4-{ Pd[4,5-( OCH 2 O) C 6 H 2 C(H)= N ]} 2 C 6 H 4( LL) 2] [ PF 6] 2[ LL = Ph 2 PCH(CH 3) PPh 2, Ph 2 P(CH 2) n PPh 2, n = 2, 3, 4 , 3d, 4d, 5d, 6d]. The influence of ring size on the phosphorus chemical shift is discussed. The compounds were characterized by microanalysis (C, H, N), IR and 31P-{ 1H} and 1H NMR spectroscopy. The structure of the dinuclear cyclometallated palladium(II) complex [1,4-{ Pd[2,4-( MeO) 2 C 6 H 2 C(H)= N ]} 2 C 6 H 4{ Ph 2 P(CH 2) 3 PPh 2−PP} 2][ PF 6] 2 is described. There are two different crystallographic molecules per asymmetric unit.