A Pentanuclear Cu/Co/Ni Complex with 2‐(Dimethylamino)ethanol – Observation of a Rare Molecular Structure Type and Its Place in General Structural Types: An Analysis of the Cambridge Structural Database

Abstract

Heterotrimetallic complex [CuII2CoIINiII2(Me2Ea)5Cl5(H2O)]·CH3CN·H2O has been prepared in a one‐pot reaction of zero‐valent copper with cobalt and nickel chlorides in an acetonitrile solution of 2‐(dimethylamino)ethanol (HMe2Ea) in the open air. The metal stoichiometry obtained by atomic absorption analysis was further confirmed by single‐crystal X‐ray diffraction investigations. The pentanuclear molecule is formed by a previously unknown combination of incomplete cube M3(μ3‐X)(μ‐X)3 and triangle bipyramidal M3(μ3‐X)2(μ‐X)2 fragments, resulting in a zigzag arrangement of metal centers within one molecule. This type of arrangement is very uncommon for pentanuclear complexes and in particular for complexes with an odd number of metal centers. A search of the Cambridge Structural Database showed that the number of coordination compounds possessing an even number of metals is significantly greater than those containing an odd number. Possible reasons for such a distribution, as well as the synthetic and structural features of the presented compound, are discussed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Polynuclear Heterometallic Complexes from Metal Powders: The “Direct Synthesis” Approach

“…Although this concept was not used in our investigations, the idea of MSTs was found to be appealing to compare the structures of related compounds. The study of the statistical distribution of MSTs35 within the Cambridge Structural Database46 revealed some widespread and rare MSTs of different nuclearities, allowing the coordination cores of novel complexes to be classified according to their rarity. Clearly, the prevalence of the MSTs depends on the topology.…”

“…Screening of the reaction system Cu 0 + CoCl 2 + NiCl 2 + HMe 2 Ea revealed that complex 30 can be obtained with a Cu/Co/Ni ratio close to 2:1:2. When a ratio of 1:1:1 was used, the heterotrimetallic complex 31 with a different structure35 was obtained [reaction (38)].…”

“…In contrast to 29 , the metal centres in 31 do not lie in a plane. It was noted that compound 31 was the first example of a Cu II /Co II /Ni II heterotrimetallic complex 35. Although the elemental analysis and coordination environments suggested the exact positions of metals in 31 (the same as in 29 ), one cannot exclude a small degree of metal scrambling at the Co II and Ni II sites.…”

“…Solvated CH 3 CN and water molecules have been omitted for clarity. Colour codes: Cu, teal; Co, red‐violet; Ni, green; O, red; N, blue; C, light grey; Cl, light green; see ref 35…”

Nickel, palladium and platinum

“…13 The pentanuclear aminoalkoxide complex [Cu II 2 Co II Ni II 2 (Me 2 NC 2 H 5 O) 5 Cl 5 (H 2 O)] has been prepared in a one-pot reaction of zero-valent copper with cobalt and nickel chlorides and has a zigzag arrangement of metal centres within one molecule formed by incomplete cube fragments joined by common faces. 14…”