TY - JOUR
T1 - Long magnetic relaxation time of tetracoordinate Co2+ in imidazo[1,5-a] pyridinium-based (C13H12N3)2[CoCl4] hybrid salt and [Co(C13H12N3)Cl3] molecular complex
AU - Vassilyeva, Olga Yu
AU - Buvaylo, Elena A.
AU - Kokozay, Vladimir N.
AU - Skelton, Brian W.
AU - Rajnák, Cyril
AU - Titiš, Ján
AU - Boča, Roman
PY - 2019/6/27
Y1 - 2019/6/27
N2 - The novel organic-inorganic hybrid salt [L]2[CoCl4] (1) and molecular complex [CoLCl3] (2), where L+ is 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium cation, feature simple {CoCl4} and {CoCl3N} tetrahedral environments of negligible (1) and a slightly higher distortion (2) that are responsible for rather low positive magnetic anisotropy of CoII ion with D/hc = 12.1(6) (1) and 19.4(15) cm-1 (2). Both compounds exhibit field-induced slow magnetic relaxation with three relaxation channels [low- (LF), intermediate- and high-frequency (HF) modes] that is frequency and field dependent. With the increased DC field, the peaks referring to the LF relaxation path are moved to lower frequencies so that the applied DC field causes prolongation of the relaxation time. The opposite is true for the HF relaxation branch: the peak is moved to higher frequencies. Considering the simplicity of the coordination environment and moderate magnetic anisotropy of the metal ion in 1 and 2, the compounds are unique with respect to the remarkably long relaxation time for a given applied DC field and temperature: τLF = 0.54(4) s at BDC = 1.0 T and T = 2.0 K for 1, and τLF = 1.8(2) s at BDC = 1.2 T and T = 1.9 K for 2.
AB - The novel organic-inorganic hybrid salt [L]2[CoCl4] (1) and molecular complex [CoLCl3] (2), where L+ is 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium cation, feature simple {CoCl4} and {CoCl3N} tetrahedral environments of negligible (1) and a slightly higher distortion (2) that are responsible for rather low positive magnetic anisotropy of CoII ion with D/hc = 12.1(6) (1) and 19.4(15) cm-1 (2). Both compounds exhibit field-induced slow magnetic relaxation with three relaxation channels [low- (LF), intermediate- and high-frequency (HF) modes] that is frequency and field dependent. With the increased DC field, the peaks referring to the LF relaxation path are moved to lower frequencies so that the applied DC field causes prolongation of the relaxation time. The opposite is true for the HF relaxation branch: the peak is moved to higher frequencies. Considering the simplicity of the coordination environment and moderate magnetic anisotropy of the metal ion in 1 and 2, the compounds are unique with respect to the remarkably long relaxation time for a given applied DC field and temperature: τLF = 0.54(4) s at BDC = 1.0 T and T = 2.0 K for 1, and τLF = 1.8(2) s at BDC = 1.2 T and T = 1.9 K for 2.
UR - http://www.scopus.com/inward/record.url?scp=85070088338&partnerID=8YFLogxK
U2 - 10.1039/c9dt01642b
DO - 10.1039/c9dt01642b
M3 - Article
C2 - 31268102
AN - SCOPUS:85070088338
VL - 48
SP - 11278
EP - 11284
JO - Dalton Transactions: the international journal for inorganic, organometallic and bioinorganic chemistry
JF - Dalton Transactions: the international journal for inorganic, organometallic and bioinorganic chemistry
SN - 1477-9226
IS - 30
ER -