Abstract
Reactions of IrCl3·xH2O with the ligands, 2-[(phenylamino)phenylazo]pyridine (HL1a) and 2-[(p-tolylamino)phenylazo]pyridine (HL1b) produce [Ir(L1)2]Cl (L1 = L1a, [1]Cl and L1 = L1b, [2]Cl) along with many unidentified products. The iridium complexes have been characterized by various techniques such as X-ray crystallography, mass spectrometry, 1H and 13C NMR, cyclic voltammetry and absorption studies. The complex [1]ClO4 crystallises in triclinic space group. The crystallographic data have been determined. Notably, the Ir-N (azo) lengths are short (av. 1·9875(4) Å) as compared to the remaining four Ir-N lengths (av. 2·052(5) Å). There is significant degree of ligand backbone conjugation in the coordinated ligands, which result in shortening of the C-N lengths on the other side of the middle phenyl ring and also in lengthening of the diazo (N=N) lengths. The complexes display multiple low energy transitions ranging between 1010 and 450 nm. These are electro active and show three reversible redox responses in the potential range, +1·5 V to −1·5 V. The cathodic potential responses are ascribed as ligand reductions, while the redox process at the anodic potential occurs at a mixed metal-ligand (HOMO) orbital.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Das S, Banerjee P, Peng S-M, Lee G-H, Kim J and Goswami S 2006 Inorg. Chem. 45 562
Sanyal A, Banerjee P, Lee G-H, Peng S-M, Hung C-H and Goswami S 2004 Inorg. Chem. 43 7456
Kamar K K, Das S, Hung C-H, Casteñeiras A, Kuźmin M D, Rillo C, Bartolomé J and Goswami S 2003 Inorg. Chem. 42 5367
Kamar K K, Saha A, Casteñeiras A, Hung C-H and Goswami S 2002 Inorg. Chem. 41 4531
Kamar K K, Saha A and Goswami S 2002 Proc. Indian Acad. Sci. (Chem. Sci.) 114 339
Saha A, Ghosh A K, Majumdar P, Mitra K N, Mondal S, Rajak K K, Falvello L R and Goswami S 1999 Organometallics 18 3772
Saha A, Majumdar P and Goswami S 2000 J. Chem. Soc., Dalton Trans. 1703
Saha A, Majumdar P, Peng S-M and Goswami S 2000 Eur. J. Inorg. Chem. 2631
Das C, Saha A, Hung C-H, Lee G-H, Peng S-M and Goswami S 2003 Inorg. Chem. 42 198
Goswami S, Mukherjee R and Chakravorty A 1983 Inorg. Chem. 22 2825
Bryndza H E and Tam W 1988 Chem. Rev. 88 1163
Fryzuk M D and Montgomery C D 1989 Coord. Chem. Rev. 95 1
Panda M, Das C, Lee G-H, Peng S-M and Goswami S 2004 Dalton Trans. 2655
Yutaka T, Obara S, Ogawa S, Nozaki K, Ikeda N, Ohno T, Ishii Y, Sakai K and Haga Masa-aki 2005 Inorg. Chem. 44 4737, and references therein
Sawyer D T and Roberts J L Jr 1974 Experimental electrochemistry for chemists (New York: Wiley) pp 167–215
Sheldrick G M 1990 Acta Crystallogr. A46 467
Sheldrick G M 1997 SHELXL-97 Program for the refinement of crystal structures, University of Göttingen: Göttingen, Germany
Geary W J 1971 Coord. Chem. Rev. 7 81
Bruin B De, Bill E, Bothe E, Weyhermuller T and Wieghardt K 2000 Inorg. Chem. 39 2936
Matsumoto N, Motoda Y, Matsuo T, Nakashima T, Re N, Dahan F and Tuchagues J-P 1999 Inorg. Chem. 38 1165
Pramanik N C, Pramanik K, Ghosh P and Bhattacharya S 1998 Polyhedron 17 1525
Allen G C, El-Sharkawy G A M and Warren K D 1972 Inorg. Chem. 11 51
Acharyya R, Basuli F, Wang R-Z, Mak T C W and Bhattacharya S 2004 Inorg. Chem. 43 704
Mealli C and Proserpio D M 1990 J. Chem. Educ. 67 399
Poison M, Fracasso S, Bertolasi V, Ravaglia M and Scandola F 2004 Inorg. Chem. 43 1950
Das C, Ghosh A K, Hung C-H, Lee G-H, Peng S-M and Goswami S 2002 Inorg. Chem. 41 7125
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Panda, M., Das, C., Hung, CH. et al. Synthesis, structure, redox and spectra of green iridium complexes of tridentate azo-aromatic ligands. J Chem Sci 119, 3–9 (2007). https://doi.org/10.1007/s12039-007-0002-z
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12039-007-0002-z