STUDIES ON METAL COMPLEXES WITH NSO DONOR LIGAND Presented by Shehnaz H Solanki Guide Dr. Sujit Baran Kumar Department of Chemistry Faculty of Science The Maharaja Sayajirao University of Baroda

Contents: Introduction Objectives Experimental Work Results and Discussion Conclusion References

INTRODUCTION Schiff bases derived from an amino and carbonyl compound are an important class of ligands that coordinate to metal ions via azomethine nitrogen and have been studied extensively. In azomethine derivatives, the C=N linkage is essential for biological activity and several azomethine has been reported to possess remarkable antibacterial, antifungal, anticancer and antimalarial activities [1]. Schiff-base complexes are considered to be among the most important stereo chemical models in main group and transition metal coordination chemistry due to their preparative accessibility and structural variety[2]. It is well known that N and S atoms play a key role in the coordination of metals at the active sites of numerous metallobiomolecules [3]. Schiff base metal complexes have been widely studied because they have industrial, antifungal, antibacterial, anticancer and herbicidal applications [4]. Chelating ligands containing N, S and O donor atoms show broad biological activity and are of special interest because of the variety of ways in which they are bonded to metal ions.

OBJECTIVES Syntheses and characterization of monoprotic tridentate N, O and S-coordinated ligand 2-((E)-(2,2dimethoxyethylimino)methyl)phenol (L). Syntheses of square planer and octahedral complexes of the type [ML2] where M = Cu2+ and Ni2+ and square planar complexes of the type [CdLX], where X = NCS-, NCO-, N3-. Characterization of the ligand and complexes by physico-chemical methods and different spectroscopic techniques such as 1H NMR, FTIR, UV-VIS and single crystal X-ray diffraction study etc. Chelating ligands containing N, S and O donor atoms show broad biological activity and are of special interest because of the variety of ways in which they are bonded to metal ions. .

Synthesis of 2-((E)-(2-(methylthio)phenylimino)methyl)phenol Experimental Work Synthesis of 2-((E)-(2-(methylthio)phenylimino)methyl)phenol Ligand Mol.Wt. Solubility Color M.P(⁰C) % Yield L 243.32 CH₃CN, CH2Cl2 Yellow 188 82 %

Synthesis of complexes Syntheses of [ML2] type complexes [M = Cu(II) and Ni(II)]

Synthesis of [CdLX] type complexes

Molecular Formula (Mol.Wt.) RESULTS AND DISCUSSIONS Microanalysis data Compound Colour Molecular Formula (Mol.Wt.) % Yield % C % H % N Theo. Prac. Ligand Yellow C14H13NOS 243.32 82% 69.11 69.42 5.39 5.32 5.76 5.55 [CuL2] Green C28H24N2CuO2S2 548.18 64% 61.35 61.68 4.41 4.4 5.11 5.12 [NiL2] C28H24N2NiO2S2 543.33 67% 61.9 61.56 4.45 4.46 5.16 5.18 [CdLN3] C15H15CdN4O5 411.78 60% 43.75 43.9 3.67 3.66 13.61 13.71 [CdLNCO] C15H15CdN2O2S 66% 46.67 46.48 3.61 6.8 6.68 [CdLNCS] C16H15CdN2OS2 427.84 62% 44.92 44.61 3.53 3.49 6.39

1H NMR Spectrum of Ligand

1H NMR Spectrum of Ligand

IR Spectrum of [CuL2]

IR Spectrum of [NiL2]

IR Spectrum of [CdLN3]

IR Spectrum of [CdLNCO]

IR Spectrum of [CdLNCS]

IR data of complexes Compound (C=N) cm-1 (C-S) cm-1 (N3)/NCO/NCS cm-1 Ligand 1610 643 - [CuL2] 1604 645 [NiL2] 1601 [CdLN3] 1603 635 2059 [CdLNCO] 625 2162 [CdLNCS] 1605 664 2063

Electronic spectra of the complexes

Electronic spectral data, conductance and magnetic property of complexes Compounds Electronic spectra λmax ( ε (mol-1cm-1) Conductance M (Ω-1mol-1cm2) in CH3CN Magnetic moment μeff (BM) [CuL2] 231(25563),398(5969), 679(127) 8 1.79 [NiL2] 227(23633), 398(6677), 679(1314) 12 2.88 Ligand 211(12671),266(10839), 353(05155) -

Single crystal structure of [CuL2] complex

Single crystal structure of [NiL2] complex

Absorption coefficient (mm-1) 1.085 1.087 2.945 F(000) 499 1698 1128 Ligand [CuL2] [NiL2] Empirical formula C14H13NOS C42H36Cu1.5N3O3S3 C28H24N2 Ni O2S2 Formula weight 243.32 822.23 543.33 Temperature (K) 293(2) Wavelength (Ǻ) 1.54184 0.71073 Crystal system Monoclinic Space group P21/n P21/c a (Ǻ) 13.8716(4) 11.1682(4) 12.8181(3) b (Ǻ) 12.0501(3) 21.9010(8) 12.1054(3) c (Ǻ) 7.37411(19) 15.3682(6) 15.9960(4) () 90.00 () 100.893(4) 95.573(2) () Volume (Ǻ3) 1232.62(5) 3691.3(2) 2470.34(10) Z 4 Density (Mg/m3) 1.265 1.480 1.461 Absorption coefficient (mm-1) 1.085 1.087 2.945 F(000) 499 1698 1128 Theta range for data collection() 4.8390 to 72.0630 3.7140 to 28.0900 3.6110 to 72.1280 Index ranges -16≤h≤13, -13≤k≤14, -6≤l≤8 -13≤h≤14, -29≤k≤29, -19≤l≤20 -15 ≤ h ≤ 15, -14 ≤ k ≤ 14, -19 ≤ l ≤ 16 Reflections collected 3118 26416 23763 Independent reflections 2120 [R(int) = 0.0197] 8683 [R(int) = 0.0299 ] 4822 [R(int) = 0.0629] Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.78997and 1.0000 0.78729 and 1.0000 0.25865 and 1.0000 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 2120 / 0 / 155 8683/ 0 / 487 4822/0/324 Goodness-of-fit on F2 1.051 1.052 1.043 Final R indices [I>2sigma(I)] R1 = 0.0532, wR2 = 0.1431 R1 = 0.0412, wR2 = 0.0919 R1 = 0.0510 wR2 = 0.1408 R indices (all data) R1 = 0.0564, wR2 = 0.1474 R1 = 0.0638, wR2 = 0.1019 R1 = 0.0538, wR2 = 0.1448

Selected bond lengths and angles of complexes [CuL2] and [NiL2] Bond Angles (°) Cu(1)–O(1) 1.9222(18) O(1)-Cu(1)-O(1)i 180.0 Cu(1)–O(1)i O(1)-Cu(1)-N(1)i 90.74(8) Cu(1)–N(1) 1.985(2) N(1)-Cu(1)-N(1)i Cu(1)–N(1)i O(3)-Cu(2)-N(2) 153.12(18) Cu(2)–O(2) 1.9104(16) N(3)-Cu(2)-N(2) 97.24(8) Cu(2)–O(3) 1.9117(17) O(2)-Cu(2)-N(2) 91.17(8) Cu(2)–N(3) 1.9994(19) O(3)-Cu(2)-N(3) 91.81(8) Cu(2)–N(2) 2.008(2) O(2)-Cu(2)-O(3) 89.38(7) O(1)-Cu(1)-N(1) 89.26 [NiL2] Ni(1)-O(1) 1.9944(17) O(1)-Ni(1)-N(1) 92.13(8) Ni(1)-O(2) 2.0231(17) N(1)-Ni(1)-N(2) 174.75(8) Ni(1)-N(1) 2.028(2) O(1)-Ni(1)-S(1) 171.37(5) Ni(1)-N(2) 2.036(2) O(2)-Ni(1)-S(2) 168.74(5) Ni(1)-S(1) 2.4748(7) S(1)-Ni(1)-S(2) 88.08(2) Ni(1)-S(2) 2.4810(7) N(2)-Ni(1)-S(2) 93.76(6)

CONCLUSION We have synthesized tridentate NOS co-ordinated ligand 2-((E)-(2 (methylthio)phenylimino)methyl) and the ligand was characterized by different spectroscopic studies such as 1H NMR, FT-IR and single crystal diffraction studies. Two mononuclear bis copper(II) complexes of the type [CuL2] and Nickel(II) complexes of the type [NiL2] and three mononuclear cadmium(II) complexes of the type [CdLX] where X = NCS-, N3-, NCO- have been synthesized by the reaction of the ligand in combination of different halide or pseudohalides. The complexes were characterized by elemental analyses, FT-IR, UV-Visible spectroscopic, conductivity measurement, magnetic studies and crystal structure of the ligand and complexes [CuL2] and [NiL2] have been solved by single crystal X-Ray diffraction studies and it shows that [CuL2] complex have distorted square planar geometry and [NiL2] complex have distorted octahedral geometry.

References : [1] [2] [3] [4] [5] [6] [7] S. Sasi, M.R.P. Kurup, E. Suresh, J. Chem. Crystallogr. 37 (2007) 31. L.-J. Liu, Synth. React. Inorg. Met. Org. Chem. 41 (2011) 531. Singh; M.S. Barwa; P. Tyagi; Eur. J. Med. Chem .42( 2007) 394-402. M. Yildiz.; B. Dulger; S. Y. Koyuncu ; B. M.Yapici .J. Indian Chem. Soc 81(2004)7-12. L. J. Farrugia, J. Appl. Cryst. 32(1999) 837. S. Mandal, A.K. Rout, M. Fleck, G. Pilet, J. Ribas, D. Bandyopadhyay, Inorg. Chim. Acta 363 (2010) 2250. S. Chandra; J. Sangeetika; J. Indian Chem. Soc. 81 ( 2004) 203-206.