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In Situ Formation of Semichelating Ligands: A Strategy for Tuning the Magnetic Coupling in Azide‐Bridged Copper(II) Complexes
Author(s) -
Shi WenBo,
Cui AiLi,
Kou HuiZhong
Publication year - 2014
Publication title -
chempluschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.801
H-Index - 61
ISSN - 2192-6506
DOI - 10.1002/cplu.201300304
Subject(s) - chemistry , azide , sodium azide , copper , crystallography , imidazole , ether , medicinal chemistry , pyrazole , stereochemistry , organic chemistry
Five Cu II complexes of trinuclear [Cu 3 (L 1 ) 2 (N 3 ) 6 ] ( 1 ), one‐dimensional chain [Cu 5 (L 2 ) 2 (N 3 ) 10 ] n ( 2 ), trinuclear [Cu 3 (L 3 ) 2 (N 3 ) 6 ] ( 3 ) and dinuclear [Cu 2 (L 4 ) 2 (N 3 ) 2 Cl 2 ] ( 4 ) and [Cu 2 (L 5 ) 2 (N 3 ) 2 Cl 2 ] ( 5 ) (L 1–5 =RCH 2 OR′, R=substituted pyrazole or imidazole, R′=Me, Et or n Pr) were synthesized by the reaction of CuCl 2 ⋅2 H 2 O, sodium azide with RCH 2 Cl in CH 3 OH, C 2 H 5 OH or n‐ C 3 H 7 OH. The ether ligands L 1 and L 2 can be alternatively prepared by the alcoholysis of RCH 2 Cl in the presence of sodium azide, whereas the ligands L 3–5 form in corresponding alcohols without azide. For complexes 1 – 5 , the oxygen atom of the ether ligands is located at the Jahn–Teller axis of Cu II with the long CuO separations of 2.377(3)–2.830(3) Å. The nitrogen atoms of bridging azides are located in the equatorial or basal planes of Cu II ions, favoring strong magnetic coupling. The Cu‐N azido ‐Cu bridging angles in complexes 1 – 3 are 98.8(2)°–101.6(1)°, leading to ferromagnetic coupling, whereas the Cu‐N azido ‐Cu angles in complexes 4 and 5 are close to 103°, leading to antiferromagnetic coupling.