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Synthesis, Structure and Magnetic Properties of Two Cobalt(II) Dicyanamide (dca) Complexes with Heterocyclic Nitrogen Donors Tetra(2‐pyridyl)pyrazine (tppz) and 2,4,6‐Tri(2‐pyridyl)‐1,3,5‐triazine (tptz): [Co 2 (tppz)(dca) 4 ]·CH 3 CN and [Co(tptz)(dca)(H 2 O)](dca)
Author(s) -
Luo Jun,
Qiu Lijuan,
Liu Baoshu,
Zhang Xinrong,
Yang Feng,
Cui Lili
Publication year - 2012
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201100553
Subject(s) - dicyanamide , chemistry , crystallography , pyrazine , dimer , cobalt , octahedron , ligand (biochemistry) , molecule , cationic polymerization , antiferromagnetism , metal , magnetic susceptibility , crystal structure , stereochemistry , inorganic chemistry , polymer chemistry , biochemistry , ionic liquid , receptor , physics , organic chemistry , condensed matter physics , catalysis
Two new transition metal dicyanamide complexes [Co 2 (tppz)(dca) 4 ]·CH 3 CN ( 1 ) [tppz=tetra(2‐pyridyl)pyrazine, dca=dicyanamide] and [Co(tptz)(dca)(H 2 O)](dca) ( 2 ) [tptz=2,4,6‐tri(2‐pyridyl)‐1,3,5‐triazine] were synthesized and characterized by single crystal X‐ray diffraction analysis. In 1 each cobalt(II) atom is coordinated to three dca anions and one tppz molecule to form a distorted octahedral geometry, the neigbour two cobalt(II) atoms are bridged by one tppz ligand to form a dimer, then the cobalt(II) atoms in each dimer are joined together to form a ladder chain structure. In 2 the coordination geometry around the central metal is also distorted octahedral, each cobalt(II) atom is coordinated by two dca anions, one tptz molecule and one water ligand to form a cationic part, and the cationic part is linked with the free dca anions via the electrostatic attraction to give an infinite chain structure. Magnetic susceptibility measurement in the range of 2–300 K indicates that there are antiferromagnetic couplings between adjacent metal ions in 1 ( T >29 K, ( =−9.78 K, C =4.92 cm 3 ·K·mol −1 ) and ferromagnetic couplings in 2 ( T >150 K, ( =7.97 K, C =2.59 cm 3 ·K·mol −1 ) respectively.