@article{oai:kanazawa-u.repo.nii.ac.jp:00000829, author = {井原, 良訓 and 鈴木, 正樹 and 上原, 章 and Ihara, Yoshinori and Satake, Yasuhiro and Suzuki, Masatatsu and Uehara, Akira}, issue = {12}, journal = {Bulletin of the Chemical Society of Japan}, month = {Jan}, note = {The thermochemical changes in coordination structure of diaquabis(N,N- or N,N′,-dialkylethylenediamine)nickel(II) complexes ([Ni(H2O)2(diamine)2]X2·nH2O) were reinvestigated by means of TG-DTA and electronic spectroscopy at room and elevated temperatures, where diamine is N,N (or N,N′-dimethylethylenediamine (NN- or NN′-dmen) or N,N-(or N,N′)-diethylethylenediamine (NN- or NN′-deen); X is Cl−, Br−, I−, or NO3−; n is 0, 1, 2, or 3. The diaqua complexes prepared were all trans except for cis-[Ni(H2O)2(NN-dmen)2]I2. The trans complexes with the symmetric (N,N′-dialkylsubstituted) diamines brought about a deaquation-anation upon heating, retaining the original trans configuration, while those with the asymmetric (N,N-dialkylsubstituted) diamines transformed into the cis complexes. In the case of the NN-dmen complexes, cis-halogenoaqua species were isolated as a stable intermediate during the thermal reactions. The complex nitrates changed to trans-dinitrato or cis-mononitrato species depending upon the diamines. The effects of the N-substituents in the diamines and of the anions on the patterns of thermal reactions were also discussed.}, pages = {3647--3652}, title = {Cis-Trans Isomerism among the Octahedral Diaquabis(N,N- or N,N′-dialkylethylenediamine)nickel(II) Complexes and Their Thermal Reaction Products}, volume = {64}, year = {1991} }