J. Indian Chern. Soc., Vol. 76, March 1999, pp. 155-156 NOTE Complexing behaviour of 4-benzylideneamino-3-methyl-1-piperidino- methyl-1,2,4-triazole-5-thione towards some transition metals "' Biju Mathew, B. Narayana and B. Ramachandra Department of Studies in Chemistry, Mangalore University, Mangalagangothri-574 199, India Manuscript received 14 May 1997, revised 24 June 1998, accepted 12 October 1998 The complexes of bivalent Cd, Hg, Zn, Ni, Co, Ru and Pd with 4-benzylideneamino-3-methyl-1-piperidinomethyl-1,2,4-triazole-5-thione have been prepared and The present paper discusses the preparation of complexes of bivalent Cd, Hg, Zn, Ni, Co, Ru and Pd with 4-ben- zy lideneamino-3-methy 1-1-piperidinomethyl-1,2,4-triazole- 5-thione (BMPT). The complexes have been characterised on the basis of analytical, magnetic, thermal, conductance and spectral data. Results and Discussion The analytical results (Table 1) show that Cdii, Hgn, znn and Pd 11 form MLC1 2 type complexes, while Con, Niii and Ru 11 from MLC1 2 type complexes with two molecules of coordinated water. All the complexes are diamagnetic with the exception of the Co 11 and NiH complexes. The ob- served magnetic moments of Ni 11 -BMPT and Co 11 -BMPT complexes are 3.14 and 5.02 B.M. respectively, as ex- pected. The molar conductance values of the complexes (4.7- 31.0 n- 1 mol- 1 cm 2 ) indicate that they are non-electrolytes and neutral in nature. The thermogravimetric analysis of the complexes of BMPT showed that the con, NiH and Ru 11 complexes contain coordinated water molecules. A Joss in weight is observed at 100-2000. The number of water molecules coordinated is found to be two in the Co 11 • Ni 11 and Ru 11 complexes. All other complexes are stable upto 200° and decompose in two major steps. The ground state of Run in octahedral field is 1 A 1 g and the excited states corresponding to qg eg configuration are 3 T1g, 3 T 2 g, 1 T 1 g and 1 T 2 g in the increasing order of energy. Hence four transitions can be expected - two spin-forbid- Table 1. Analytical and electronic spectral data of the complexes • Complex [Cd(Ct6H2tNsS)Ch] [Hg(Ct6H2tNsS)Ch] [Zn(Ct6H2tNsS)Ch] [Ni(Ct6H2tN5S)Cb. 2H20] [Co(Ct6H2tNsS)Ch. 2H20] [Ru(Ct6H2tNsS)Ch.2H20] Metal%: Found/ (Calcd.) 22.56 (22.54) 34.16 (34.18) 14.43 (14.48) 12.21 (12.20) 12.26 (12.24) 19.28 (19.31) 21.58 (21.59) em 823o" 18518 20618 16690 20360 24390 19880 20512 24691 • All compounds gave satisfactory C, H, N and S analyses, aCalculated. Assignment 10Dq B 4 Tt 8 (F) --+ 4 T28(F) 4Ttg(F) --+ 4 A2 g(F) 4 Ttf(F) 10288 963.0 0.86 Atg-+ Ttg 1 Atg -+ 1 T2g 22195 251.8 0.41 1 Atg -+ 1 T2g 1 Atg -+ 1 A2g 1 Atg-+ 1 Btg 1 Atg -+ 1 Eg 155