Ferrocene phosphinocarboxamides, 1-(diphenylphosphino)-1'-{N-[(2-pyridyl)methyl]carbamoyl}ferrocene (1) and 1-(diphenylphosphino)-1'-{N-[2-(2-pyridyl)ethyl]carbamoyl}ferrocene (2) were prepared from 1-(diphenylphosphino)-1'-ferrocenecarboxylic acid and studied as ligands for palladium. Starting with [PdCl2(cod)], the reactions at a 2 : 1 ligand-to-metal ratio gave uniformly the bis-phosphine complexes [PdCl2(L-kappaP)2] (3, L = 1; 4, L = 2) whereas those performed at a 1 : 1 ratio yielded distinct products: [PdCl2(1-kappa(2)P,N)] (5) with 1 coordinating as a trans-spanning P,N-donor, and the symmetric, P,N-bridged dimer [(micro-2-N,P)2{PdCl2}2] (6), respectively. The crystal structures of 1, 2, 4.4CHCl3, 5.AcOH, and 6.8CHCl3 as determined by X-ray diffraction showed the compounds to form well defined solid-state assemblies through hydrogen bonds. Testing of the phosphinocarboxamides in the palladium-catalysed Suzuki cross-coupling reaction revealed 1 and 2, combined with Pd(OAc)2 to form efficient catalysts for the reactions of aryl bromides while aryl chlorides coupled only when activated with electron-withdrawing groups.

The synthesis and characterisation of a series of novel complexes of type [((tmeda)M-OC(O)-fc-(micro-CO(2)))(2)(micro-H(2)O)] (M = Co, ; M = Ni, ), zwitter-ionic [((pmdta)(H(2)O)Cu(+)-OC(O)-fc-CO(2)(-))(CH(3)OH)] (), and coordination polymer [(tmeda)Cu((OC(O))(2)fc)](n) () (fc = ferrocene-1,1'-diyl, (eta(5)-C(5)H(4))(2)Fe; tmeda = N,N,N',N'-tetramethylethylenediamine; pmdta = 1,1,4,7,7-N,N,N',N'',N''-pentamethyldiethylenetriamine) composed of ferrocene dicarboxylates and [(tmeda)/(pmdta)M](2+) entities is reported. These complexes could be prepared from [M(NO(3))(2)(tmeda)] (M = Co, ; M = Ni, ; M = Cu, ) and [Cu(NO(3))(2)(pmdta)] (), respectively, with stoichiometric amounts of 1,1'-ferrocene dicarboxylic acid () in presence of [n-Bu(4)N]OH-H(2)O. The molecular structures of , , , and in the solid state have been determined by single-crystal X-ray structure analysis. Electrochemical and UV-vis-NIR spectroscopic studies of these complexes are discussed in terms of electronic communication between the redox-active transition metals. In addition, the magnetic properties of and have been studied by susceptibility measurements vs. temperature. In complex , the two cobalt(ii) ions are antiferromagnetically coupled, while in the Ni-Ni coupling is ferromagnetic with J approximately +2.2(1) cm(-1).

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The isomeric ferrocene phosphine-carboxamides, 1-(diphenylphosphino)-1'-{[N-(2-pyridyl)-methyl]carbamoyl}ferrocene (1) and 1-(diphenylphosphino)-1'-{[N-(4-pyridyl)methyl]carbamoyl}ferrocene (2) have been studied as ligands in group-12 metal bromide complexes. The reactions of 1 with CdBr2 x 4H2O and HgBr(2) at 1:1 mole ratio gave the discrete tetracadmium complex [Cd2(micro-Br)2(-1kappa2O,N2)2[micro-1kappa2O,N2:2kappaP-(C5H4N)CH2NHC(O)fcPPh2-CdBr3]2] (7; fc = ferrocene-1,1'-diyl) and the halogeno-bridged dimer [[Hg(micro-Br)Br(-kappaP)]2] (8), respectively. In the presence of acetic acid, the CdBr2-1 system furnished a zwitterionic complex featuring protonated 1 as the P-monodentate donor, [CdBr3[Ph2PfcC(O)NHCH2(C5H4NH)-kappaP]] x H2O (6 x H2O). Under neutral conditions, compound , whose terminal donor groups are better arranged for the formation of extended assemblies, gave rise to one-dimensional coordination polymers [MBr2[micro(P,N)-]](n) (M = Cd, 4; M = Hg, ). The crystal structures of 2 x H2O, its corresponding phosphine oxide (3 x H2O), and complexes 4, 5, 6 x H2O, and have been determined, revealing extensive hydrogen bonding interactions in the solid state.