Cooperative Binding of Nitrile Moieties Within a Bimetallic Pocket: Enforcing Side-On π-Interaction With a High-Spin Nickel(II) Site

Bis(cyanamide-κN)[4-(1H-imidazol-1-yl)phenol-κN3]bis(nitrato-κO)copper(II)

“…For background to related compounds, see: Ferlay et al (1995); Ribas et al (1999). For related structures, see: Becker et al (2000); Berger & Schnick (1994); Liao & Dronskowski (2006); Liu et al (2005); Meyer et al (2000); Chaudhuri et al (1985); Tanabe et al (2002); Yuan et al (2004Yuan et al ( , 2007.…”

“…Dronskowski and coworkers reported the first and only carbodiimide of a magnetic transition-metal compound in 2005 (Liu et al, 2005). However, to our knowledge, structures of transition-metal cyanamide complexes are limited (Meyer et al, 2000;Chaudhuri et al, 1985;Tanabe et al, 2002;Yuan et al, 2004;Yuan et al, 2007). Since NCNHis isoelectronic with the azide anion, polymers bridged by NCNHshould also transfer favorable magnetic interactions.…”

Synthetic Models for the Active Sites of Nickel‐Containing Enzymes

“…In contrast to the latter, 76 is capable of nitrile hydration to give complexes 78 with N,O-bridging amidato groups which are assumed to be generated via initial replacement of water by the N-bound substrate within the bimetallic pocket (77). This picture is corroborated by the molecular structure of 79, which closely mimics the situation in the putative intermediate 77 [178]. The phtalazine-based system 80, reported by Barrios and Lippard [172], features bridging water molecules that exhibit rather low pK a values of 6.49 and 9.71.…”

Homo- and Heterobimetallic Precursor Catalysts for the Heck Reaction, and a Proposal for a General Catalytic Cooperativity Index

“…The majority of these systems employ homobimetallic catalyst precursors. Representative examples include bimetallic catalysts for phosphoester hydrolysis (Co 2 , [39] Cu 2 , [40,41] Zn 2 [42] ), nitrile hydration (Ni 2 , [43,44] Pd 2 [45] ), hydroformylation (Rh 2 , [25,46±48] Ru 2 [49] ), alkene [50] and alkyne [51] hydrogenation (Ir 2 ), and asymmetric epoxide ring-opening (Cr 2 ). [52] In addition, cooperative effects between two different metal centres have been invoked but not proven to be operative in the catalytic hydrogenation of cyclohexene (RuIr [53] ) and in hydroformylations (RhPd [49] ).…”