TY - JOUR
T1 - Structure-function correlations in mononuclear manganese(iii) spin crossover systems with a big conjugated hexadentate Schiff-base ligand
AU - Zhao, Sheng Ze
AU - Qin, Chun Yan
AU - Wang, Shi
AU - Yamashita, Masahiro
AU - Li, Yong Hua
AU - Huang, Wei
N1 - Funding Information:
We gratefully acknowledge financial support from the Natural Science Foundations of China (grant no. 21771110) and from the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions (grant no. YX03002).
Publisher Copyright:
© 2020 The Royal Society of Chemistry.
PY - 2020/4/14
Y1 - 2020/4/14
N2 - This paper reports the syntheses, crystal structures and magnetic properties of spin crossover (SCO) salts of formulae [Mn(naphth-sal-N-1,5,8,12)]SbF6 (1), [Mn(naphth-sal-N-1,5,8,12)]AsF6 (2), [Mn(naphth-sal-N-1,5,8,12)]PF6·1/2CH3OH (3) and [Mn(naphth-sal-N-1,5,8,12)]ClO4 (4), where (naphth-sal-N-1,5,8,12)2- (2,2′-((1E,14E)-2,6,10,14-tetraazapentadeca-1,14-diene-1,15-diyl)diphenolate) is a big conjugated hexadentate Schiff-base ligand. Magnetic susceptibility measurements demonstrated that complexes 1 and 2 showed a gradual one-step SCO between the high-spin (HS, S = 2) and low-spin (LS, S = 1) states without thermal hysteresis. The transition temperatures T1/2 of the SbF6 (1) and AsF6 (2) salts estimated from the magnetic susceptibility measurements are 164 and 171 K, respectively. The existence of the crystal solvent of complex 3 changes the supramolecular packing, leading to close π⋯π stacking interactions between the phenyl groups of the ligands. These close stacking interactions hinder the flexibility of the whole ligand, precluding the spin transformation of complex 3 and leading to its stabilization in the HS state in the temperature range of 2-300 K. For 4, crystal structure analysis indicates that the reduction in the anion size leads to close contacts between the naphthalene rings. These C-H⋯π interactions provide a means for preventing the spin crossover occurring at low temperatures.
AB - This paper reports the syntheses, crystal structures and magnetic properties of spin crossover (SCO) salts of formulae [Mn(naphth-sal-N-1,5,8,12)]SbF6 (1), [Mn(naphth-sal-N-1,5,8,12)]AsF6 (2), [Mn(naphth-sal-N-1,5,8,12)]PF6·1/2CH3OH (3) and [Mn(naphth-sal-N-1,5,8,12)]ClO4 (4), where (naphth-sal-N-1,5,8,12)2- (2,2′-((1E,14E)-2,6,10,14-tetraazapentadeca-1,14-diene-1,15-diyl)diphenolate) is a big conjugated hexadentate Schiff-base ligand. Magnetic susceptibility measurements demonstrated that complexes 1 and 2 showed a gradual one-step SCO between the high-spin (HS, S = 2) and low-spin (LS, S = 1) states without thermal hysteresis. The transition temperatures T1/2 of the SbF6 (1) and AsF6 (2) salts estimated from the magnetic susceptibility measurements are 164 and 171 K, respectively. The existence of the crystal solvent of complex 3 changes the supramolecular packing, leading to close π⋯π stacking interactions between the phenyl groups of the ligands. These close stacking interactions hinder the flexibility of the whole ligand, precluding the spin transformation of complex 3 and leading to its stabilization in the HS state in the temperature range of 2-300 K. For 4, crystal structure analysis indicates that the reduction in the anion size leads to close contacts between the naphthalene rings. These C-H⋯π interactions provide a means for preventing the spin crossover occurring at low temperatures.
UR - http://www.scopus.com/inward/record.url?scp=85083042073&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85083042073&partnerID=8YFLogxK
U2 - 10.1039/c9dt04882k
DO - 10.1039/c9dt04882k
M3 - Article
C2 - 32159185
AN - SCOPUS:85083042073
VL - 49
SP - 4293
EP - 4305
JO - Dalton Transactions
JF - Dalton Transactions
SN - 1477-9226
IS - 14
ER -