caa a22 4500 465776043 CHVBK 20180323111942.0 cr unu---uuuuu 170327e19901001xx s 000 0 eng 10.1007/BF01177465 doi (NATIONALLICENCE)springer-10.1007/BF01177465 N.m.r. characterisation of linkage isomers [Elektronische Daten] [Suthamalli Ramalingam, S. Samath] Summary: Halogenation of LnIII, CeIV and ZrOII β-diketone/β-ketoester derivatives and their mixed ligand complexes of the types Ln(AA)2(Sal) and Ln(AA)(Sal)2 by NCS, NBS and PyHBr3 yield different isomeric products depending on the nature of the solvent medium, the reagent and the reaction time. The halogenation, if carried out in glacial acetic acid, irrespective of the reagent, yields the stable S-hall, product wherein the three chelate rings remain imperturbed in respect of metal coordination. When the reaction is carried out in 5% v/v DMF-CHCl3 employingN-halosuccinimide and maintaining correct reaction times, it is possible to isolate individually three other isomeric products. The isomers prepared are Ln(OO)3, Ln(OO)2(OX), Ln(OO)(OX)2 and Ln(OX)3 where (OO) represents diketone oxygen linkage and (OX) represents diketone oxygen and substituted halogen linkage to the central metal ion. The four linkage isomers have been identified by a comparison of the number of observed3H n.m.r. or13C n.m.r. signals with those expected for a given isomer on the basis of symmetry considerations in the tris-chelated octahedral structures. Chapman and Hall Ltd., 1990 Ramalingam Suthamalli Department of Inorganic Chemistry, Madurai Kamaraj University, 625021, Madurai, India aut Samath S. Department of Inorganic Chemistry, Madurai Kamaraj University, 625021, Madurai, India aut Transition Metal Chemistry Kluwer Academic Publishers 15/5(1990-10-01), 374-378 0340-4285 15:5<374 1990 15 11243 https://doi.org/10.1007/BF01177465 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01177465 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ramalingam Suthamalli Department of Inorganic Chemistry, Madurai Kamaraj University, 625021, Madurai, India aut NATIONALLICENCE 700 1- Samath S. Department of Inorganic Chemistry, Madurai Kamaraj University, 625021, Madurai, India aut NATIONALLICENCE 773 0- Transition Metal Chemistry Kluwer Academic Publishers 15/5(1990-10-01), 374-378 0340-4285 15:5<374 1990 15 11243 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer