A family of polynuclear cobalt complexes upon employment of an indeno-quinoxaline based oxime ligand

Canaj, A. B. , Nodaraki, L. E., Ślepokura, K., Siczek, M., Tzimopoulos, D. I., Lis, T. and Milios, C. J. (2014) A family of polynuclear cobalt complexes upon employment of an indeno-quinoxaline based oxime ligand. RSC Advances, 4(44), pp. 23068-23077. (doi:10.1039/C4RA01914H)

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Abstract

The reaction of Co(OAc)2·4H2O with LH (LH = 11H-indeno[1,2-b]quinoxalin-11-one oxime) in MeOH in the presence of NEt3 forms the complex [CoIII2CoIIO(OAc)3L3]·0.5MeOH·0.2H2O (1·0.5MeOH·0.2H2O), while repeating the reaction under solvothermal conditions yielded the heptanuclear cluster [CoII7L9 (OH)2(OAc)2.7(MeO)0.3(H2O)]·4.6MeOH·3.3H2O (2·4.6MeOH·3.3H2O). Changing the starting metal salt to Co(ClO4)2·6H2O and upon the reaction with LH in the presence of NEt3 under high temperature and pressure, we managed to isolate the decanuclear cluster [CoII10L14(OH)3.6(MeO)0.4](ClO4)2·8.5MeOH·5.75H2O (3·8.5MeOH·5.75H2O), while under normal bench conditions and upon employment of pivalates in the reaction mixture complex [CoII4L4(piv)4(MeOH)2]·MeOH·H2O (4·MeOH·H2O) was formed. Furthermore, the reaction of Co(ClO4)2·6H2O with LH and aibH (2-amino-isobutyric acid) in the presence of NEt3 in MeOH gave the mononuclear complex [CoIIIL(aib)2]·3H2O (5·3H2O), while upon increasing the metal–ligand ratio cluster [CoIII2CoIIL4(aib)2(OH)2]·7.9MeOH (6·7.9MeOH) was isolated. Finally, repeating the reaction that yielded the mononuclear complex 5·3H2O under solvothermal conditions, gave the octanuclear cluster [CoII8L10(aib)2(MeO)2](ClO4)2·6.8MeOH·7H2O (7·6.8MeOH·7H2O). Variable temperature dc magnetic susceptibility studies for complexes 2, 3, 4 and 7, reveal that all clusters display dominant antiferromagnetic interactions leading to small or diamagnetic ground-states, S

Item Type:Articles
Additional Information:CJM would like to thank The Excellence Grant (ARISTEIA-2691) for funding. DIT would like to thank the 89439/2012 Grant of the Aristotle University of Thessaloniki.
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Tsanai, Mr Angelos
Authors: Canaj, A. B., Nodaraki, L. E., Ślepokura, K., Siczek, M., Tzimopoulos, D. I., Lis, T., and Milios, C. J.
College/School:College of Science and Engineering > School of Chemistry
Journal Name:RSC Advances
Publisher:Royal Society of Chemistry
ISSN:2046-2069
ISSN (Online):2046-2069
Copyright Holders:Copyright © 2014 The Royal Society of Chemistry
First Published:First published in RSC Advances
Publisher Policy:Reproduced under a Creative Commons License

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