Premium
Tuning of crystallization method and ligand conformation to give a mononuclear compound or two‐dimensional SCO coordination polymer based on a new semi‐rigid V‐shaped bis‐pyridyl bis‐amide ligand
Author(s) -
Hao Xiaoyun,
Dou Yong,
Cao Tong,
Qin Lan,
Yang Lu,
Liu Hui,
Li Dacheng,
Liu Qingyun,
Zhang Daopeng,
Zhou Zhen
Publication year - 2020
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229620004854
Subject(s) - ligand (biochemistry) , denticity , chemistry , crystallography , amide , crystallization , crystal structure , benzene , single crystal , stereochemistry , organic chemistry , receptor , biochemistry
With the new semi‐rigid V‐shaped bidentate pyridyl amide compound 5‐methyl‐ N , N ′‐bis(pyridin‐4‐yl)benzene‐1,3‐dicarboxamide ( L ) as an auxiliary ligand and the Fe II ion as the metal centre, one mononuclear complex, bis(methanol‐κ O )bis[5‐methyl‐ N , N ′‐bis(pyridin‐4‐yl)benzene‐1,3‐dicarboxamide‐κ N ]bis(thiocyanato‐κ N )iron(II), [Fe(SCN) 2 (C 19 H 16 N 4 O 2 ) 2 (CH 3 OH) 2 ] ( 1 ), and one two‐dimensional coordination polymer, catena ‐poly[[[bis(thiocyanato‐κ N )iron(II)]‐bis[μ‐5‐methyl‐ N , N ′‐bis(pyridin‐4‐yl)benzene‐1,3‐dicarboxamide‐κ 2 N : N ′]] methanol disolvate dihydrate], {[Fe(SCN) 2 (C 19 H 16 N 4 O 2 ) 2 ]·2CH 3 OH·2H 2 O} n ( 2 ), were prepared by slow evaporation and H‐tube diffusion methods, respectively, indicating the effect of the method of crystallization on the structure type of the target product. Both complexes have been structurally characterized by elemental analysis, IR spectroscopy and single‐crystal X‐ray crystallography. The single‐crystal X‐ray diffraction analysis shows that L functions as a monodentate ligand in mononuclear 1 , while it coordinates in a bidentate manner to two independent Fe(SCN) 2 units in complex 2 , with a different conformation from that in 1 and the ligands point in two almost orthogonal directions, therefore leading to a two‐dimensional grid‐like network. Investigation of the magnetic properties reveals the always high‐spin state of the Fe II centre over the whole temperature range in 1 and a gradual thermally‐induced incomplete spin crossover (SCO) behaviour below 150 K in 2 , demonstrating the influence of the different coordination fields on the spin properties of the metal ions. The current results provide useful information for the rational design of functional complexes with different structure dimensionalities by employing different conformations of the ligand and different crystallization methods.