TY - JOUR
T1 - Isomerisation in Bis(diethyltriamine)nickel(II) Thiocyanate: Synthesis, Solid-state Interconversion and X-Ray Crystallographic Study of syn-fac and mer Isomers
AU - Mukherjee, Alok K.
AU - Koner, Subratanath
AU - Ghosh, Ashutosh
AU - Chaudhuri, Nirmalendu Ray
AU - Mukherjee, Monika
AU - Welch, Alan J.
PY - 1994/8/21
Y1 - 1994/8/21
N2 - Bis(diethylenetriamine)nickel(II) thiocyanate has been found to undergo a phase transition (162-180 °C, ΔH = 29.4 kJ mol-1) involving a low-temperature ordered system (sym-fac isomer 1) and a high-temperature disordered system (mer isomer 2). Both isomers have been synthesised and characterized by X-ray crystallography. Isomer 2 is metastable and reverts to 1 in the presence of a humid atmosphere (relative humidity ca. 60% or more) as heterogeneous catalyst. Isomer 1 crystallizes in the triclinic system, space group P1̄, with a = 7.240(2), b = 8.225(3), c = 8.766(3) Å, α = 63.27(2), β = 74.07(4), γ = 65.56(2)°, Z = 1, R = 0.024. In the cationic unit, the ligand geometry around nickel(II) is nearly octahedral. Two chelating tridentate diethylenetriamine (dien) molecules with terminal amino groups in cis and secondary amino groups in trans position define the sym-fac geometry. Isomer 2 crystallizes in the cubic system, space group F4̄3m, with a = b = c = 12.373(3) Å, Z = 4, R = 0.112. The cation [Ni(dien)2]2+ is three-fold disordered about the [111] direction and the two tridentate dien molecules are co-ordinated meridionally.
AB - Bis(diethylenetriamine)nickel(II) thiocyanate has been found to undergo a phase transition (162-180 °C, ΔH = 29.4 kJ mol-1) involving a low-temperature ordered system (sym-fac isomer 1) and a high-temperature disordered system (mer isomer 2). Both isomers have been synthesised and characterized by X-ray crystallography. Isomer 2 is metastable and reverts to 1 in the presence of a humid atmosphere (relative humidity ca. 60% or more) as heterogeneous catalyst. Isomer 1 crystallizes in the triclinic system, space group P1̄, with a = 7.240(2), b = 8.225(3), c = 8.766(3) Å, α = 63.27(2), β = 74.07(4), γ = 65.56(2)°, Z = 1, R = 0.024. In the cationic unit, the ligand geometry around nickel(II) is nearly octahedral. Two chelating tridentate diethylenetriamine (dien) molecules with terminal amino groups in cis and secondary amino groups in trans position define the sym-fac geometry. Isomer 2 crystallizes in the cubic system, space group F4̄3m, with a = b = c = 12.373(3) Å, Z = 4, R = 0.112. The cation [Ni(dien)2]2+ is three-fold disordered about the [111] direction and the two tridentate dien molecules are co-ordinated meridionally.
UR - http://www.scopus.com/inward/record.url?scp=37049079820&partnerID=8YFLogxK
U2 - 10.1039/DT9940002367
DO - 10.1039/DT9940002367
M3 - Article
AN - SCOPUS:37049079820
SN - 1472-7773
SP - 2367
EP - 2371
JO - Journal of the Chemical Society, Dalton Transactions
JF - Journal of the Chemical Society, Dalton Transactions
IS - 16
ER -