Ni(en)2Ni(CN)4.nH2O (n = 2.16): structure and molecular-mechanics investigation of hydrogen bonding

Abstract

Abstract. catena-Poly[bis(ethylenediamine)nickel]-

[Au(CN)4]-as a Supramolecular Building Block for Heterobimetallic Coordination Polymers

“…Systems 4 and 5 are the first examples of [Au(CN) 4 ] - -based coordination, where polymer formation is a result of multiple cyanide bridging (2-cis and 4) through the anionic building block. Similar coordination polymers have been formed with other related anions, such as [Ni(CN) 4 ] 2- and [Pt(CN) 4 ] 2- . ,− Also, the [Au(CN) 4 ] - -based systems are quite different from previously studied [Au(CN) 2 ] - -based polymers, − as would be expected given the change in oxidation state and geometry (from linear to square planar).…”

“…One key factor is likely the decreased basicity of Au(III) vs both Au(I) cyanometalates and [M(CN) 4 ] 2- which would decrease the propensity of the cyanometalate to coordinate to another metal center, and hence decrease the likelihood of bridging cyanides. Although the square planar [Au(CN) 4 ] - has increased steric bulk as compared to a linear Au(I) cyanometalate, this is likely not causing decreased bridging, as many [Pt(CN) 4 ] 2- and [Ni(CN) 4 ] 2- bridging polymers have been reported. ,− …”

“…Cyanometalate anions have been extensively used as design elements in supramolecular coordination systems where they can act as multidentate ligands, linking numerous metal centers together to form stable, high-dimensionality coordination polymers with transition metal cations. ,, Many studies have been done with square planar cyanometalates [Pt(CN) 4 ] 2- and [Ni(CN) 4 ] 2- , indicating their usefulness in building multidimensional coordination polymers, ,− including the well-known Hofmann clathrates. , Despite this, the related [Au(CN) 4 ] - anion has received little attention in the field of supramolecular coordination chemistry. Au(III) is isoelectronic with Pt(II) and Pd(II) and thus also has the potential of displaying the aforementioned metal−metal stacking interactions.…”

(SP-4-1)-Bis{aqua[(1R,2R)-N,N′-bis(salicylidene)cyclohexane-1,2-diamine-κ4O,N,N′,O′]manganese(III)}-di-μ-cyano-κ4N:C-[dicyanonickel(II)]

“…For example, Mn III complexes are employed as catalysts for Kochi-Jacobsen-Katsuki enantioselective oxidation (Korendovych & Rybak-Akimova, 2004; Martínez et al, 2002;Reger & Janda, 2000) and metalloprotein models for photosystem II (Ashmawy et al, 1985;Aurangzeb et al, 1994;Bermejo et al, 1996). On the other hand, [Ni(CN) 4 ] 2À is known as a building block for various types of cyanide-bridged complexes (Muga et al, 2004;Shen et al, 2004;Maji et al, 2001;Č erná k & Abboud, 2002;Č erná k et al, 1990;Park & Iwamoto, 1992, 1993. For Mn III complexes with O h symmetry, the 5 D ground state may split into 5 T 2g and 5 E g terms, and Jahn-Teller distortion removes the orbital degeneracy of the 5 E g ground state to give an orbital singlet lowest in energy, either the 5 A 1g or 5 B 1g .…”