TY - JOUR
T1 - Syntheses, characterisation and solid state thermal studies of 1-(2-aminoethyl)piperidine (L), 1-(2-aminoethyl)pyrrolidine (L′) and 4-(2-aminoethyl)morpholine (L″) complexes of nickel(II): X-ray single crystal structure analyses of trans-[NiL2(CH3CN)2] (ClO4)2, trans-[NiL2(NCS)2]
AU - Laskar, Inamur Rahaman
AU - Maji, Tapas Kumar
AU - Das, Debasis
AU - Lu, Tian Huey
AU - Wong, Wing Tak
AU - Okamoto, Ken ichi
AU - Ray Chaudhuri, Nirmalendu
PY - 2001/6/30
Y1 - 2001/6/30
N2 - Reactions of nickel(II) salts with substituted ethane-1,2-diamine where one of the amine nitrogens is a part of a flexible cyclic ring, e.g. 1-(2-aminoethyl)piperidine (L), 1-(2-aminoethyl)pyrrolidine (L′) and 4-(2-aminoethyl)morpholine (L″) produce a number of complexes of the type: (i) Ni(A-A)2X2(where X = CF3CO2-, SCN-and NO2-; A-A represents L/L′/L″); (ii) Ni(A-A)2(CH3CN)2X2(X = ClO4-and NO3-); (iii) Ni(A-A)2(H2O)2X2(X = CF3SO3-, Cl-, Br-and I-); and (iv) Ni(A-A)2(H2O)4X2(X = 0.5SO42-, 0.5SeO42-and CF3SO3-). The complexes possess octahedral geometry. The major complexes upon desolvation retain trans-geometry, some of which are cis with respect to the counter-anion and a few of them are square planar. X-ray single crystal structure analyses of trans-[NiL2(CH3CN)2] (ClO4)2, trans-[NiL2(NCS)2] (violet) and trans-[NiL″2(NCS)2] (sky-blue) have been done. The violet and sky-blue thiocyanato species have blue and green coloured isomers, respectively, and these pairs of isomers are proposed to be conformational isomers. Solid state thermal investigation of the complexes has been carried out. The complexes show thermochromism due to deaquation-anation/deaquation reaction/change of conformation. Only [NiL2](ClO4)2, [NiL′2(CF3CO2)2] and [NiL″2(NO2)2] undergo thermally induced phase transition. The effect of flexible ring size on diamine has been discussed.
AB - Reactions of nickel(II) salts with substituted ethane-1,2-diamine where one of the amine nitrogens is a part of a flexible cyclic ring, e.g. 1-(2-aminoethyl)piperidine (L), 1-(2-aminoethyl)pyrrolidine (L′) and 4-(2-aminoethyl)morpholine (L″) produce a number of complexes of the type: (i) Ni(A-A)2X2(where X = CF3CO2-, SCN-and NO2-; A-A represents L/L′/L″); (ii) Ni(A-A)2(CH3CN)2X2(X = ClO4-and NO3-); (iii) Ni(A-A)2(H2O)2X2(X = CF3SO3-, Cl-, Br-and I-); and (iv) Ni(A-A)2(H2O)4X2(X = 0.5SO42-, 0.5SeO42-and CF3SO3-). The complexes possess octahedral geometry. The major complexes upon desolvation retain trans-geometry, some of which are cis with respect to the counter-anion and a few of them are square planar. X-ray single crystal structure analyses of trans-[NiL2(CH3CN)2] (ClO4)2, trans-[NiL2(NCS)2] (violet) and trans-[NiL″2(NCS)2] (sky-blue) have been done. The violet and sky-blue thiocyanato species have blue and green coloured isomers, respectively, and these pairs of isomers are proposed to be conformational isomers. Solid state thermal investigation of the complexes has been carried out. The complexes show thermochromism due to deaquation-anation/deaquation reaction/change of conformation. Only [NiL2](ClO4)2, [NiL′2(CF3CO2)2] and [NiL″2(NO2)2] undergo thermally induced phase transition. The effect of flexible ring size on diamine has been discussed.
KW - Crystal structures
KW - Diamines
KW - Isomerisation
KW - Nickel(II) complexes
KW - Thermochromism
UR - http://www.scopus.com/inward/record.url?scp=0035973139&partnerID=8YFLogxK
U2 - 10.1016/S0277-5387(01)00803-8
DO - 10.1016/S0277-5387(01)00803-8
M3 - Journal article
SN - 0277-5387
VL - 20
SP - 2073
EP - 2082
JO - Polyhedron
JF - Polyhedron
IS - 15-16
ER -