Premium
Unusual Magnetism of an Unsymmetrical Trinickel Chain
Author(s) -
Cotton F. Albert,
Murillo Carlos A.,
Wang Qingsheng,
Young Mark D.
Publication year - 2008
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200800808
Subject(s) - chemistry , crystallography , nickel , atom (system on chip) , metal , ion , open shell , unpaired electron , nitrogen , molecule , magnetism , nitrogen atom , stereochemistry , ring (chemistry) , condensed matter physics , physics , organic chemistry , computer science , embedded system
An extended metal atom chain (EMAC) compound with an unsymmetrical trinickel core and the formula [Ni 3 (dpa) 4 (CH 3 CN)](PF 6 ) 2 · 2CH 2 Cl 2 ( 1· 2CH 2 Cl 2 , dpa is the anion of 2,2′‐dipyridylamine) has the central Ni atom in an essentially square‐planar configuration. Besides having four equatorial nitrogen atoms, the two terminal metal centers have axial interactions that are notably different with one having a strongly bound acetonitrile molecule with a Ni(3)–N(3) distance of 2.108(5) Å while the other unit has a very weak interaction with an axial PF 6 anion [Ni(1) ··· F(1) separation of 2.690 Å]. In these outer units, the Ni(3) atom is pulled out of the idealized plane of the four equatorial nitrogen atoms by 0.239 Å, while in the one with an axial PF 6 anion the metal atom is pulled from the plane of the equatorial nitrogen atoms by only 0.097 Å. In 1 there are two unpaired electrons and an S = 1 state prevails from ca. 25 to 300 K. This magnetic behavior differs considerably from that of symmetrical trinickel EMACs with two strongly pyramidal terminal nickel atoms. A discussion of the effect of various axial ligands on the geometry of the terminal nickel atoms is provided. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)