Anion exchange in [Ni(η5-C5H4R)(Cl)(NHC)]. Counterion effect on the structure and catalytic activityElectronic supplementary information (ESI) available: Additional tables and figures. CCDC 972867-972870. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c3dt53352b

• Main Authors: Buchowicz, W odzimierz, Banach, ukasz, Conder, Joanna, Gu ka, Piotr A, Kubicki, Dominik, Buchalski, Piotr
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c3dt53352b

A series of novel complexes [Ni(η 5 -C 5 H 4 R)(L)(NHC)] + A − 2a-2j and [Ni(η 5 -C 5 H 5 )(A)(NHC)] 3a-3c has been obtained by anion metathesis from the corresponding chlorides 1a-1d , depending on the anion binding properties and reaction conditions. Solid-state structures of two cationic complexes ( 2c , 2j ) and two complexes with a coordinated anion ( 3a , 3c ) have been determined by X-ray diffraction revealing a trigonal planar geometry in all cases. Unexpectedly, 3c displayed unprecedented for this type of compounds temperature-dependent NMR spectra that were interpreted in terms of spin equilibrium. The cationic complexes 2 were less efficient in styrene polymerization than the parent chlorides 1 . However, the activity of 2 and 3 in Suzuki cross-coupling did not depend considerably on the counterion. Complexes [Ni(Cp)(L)(NHC)] + A − and [Ni(Cp)(A)(NHC)] were synthesised by anion exchange in [Ni(Cp)(Cl)(NHC)]. Nitrate [Ni(Cp)(NO 3 )(IMes)] shows temperature-dependent NMR spectra that were interpreted as a result of spin equilibrium.