Abstract
The synthesis, structural and magnetic characterisation of a family of Ni(ii) cages built from hydroxamate ligands is presented. Two pentanuclear 12-MCNi(ii)-4 metallacrowns [Ni5(L1) 4(MeOH)4](ClO4)2·2MeOH (1) and [Ni5(L1)4(py)5](ClO 4)2·H2O (2) (where L1H 2 = 2-(dimethylamino)phenylhydroxamic acid) share analogous, near-planar {Ni5(L1)4}2+ cores, but differ in the number and nature of the ligands located at the axial Ni(ii) sites; the addition of pyridine converting square planar Ni(ii) ions to square-based pyramidal and octahedral Ni(ii) ions, introducing extra paramagnetic metal centres which 'switch on' additional magnetic superexchange pathways. Subtle variations in the reaction scheme used to produce complexes 1 and 2 result in both a change of topology and an increase in nuclearity, through isolation of the hepta- and nonametallic complexes [Ni7(L 1H)8(L1)2(H2O) 6](SO4)·15H2O (3), [Ni 9(μ-H2O)2(L2)6(L 2H)4(H2O)2](SO4) ·29H2O (4) and [Ni9(μ-H2O) 2(L2)6(L2H)4(H 2O)2](ClO4)2·2MeOH· 18H2O (5) (where L2H2 = 2-(amino) phenylhydroxamic acid). Complementary dc magnetic susceptibility studies and DFT analysis indicate dominant antiferromagnetic exchange interactions in 1, 2, 4 and 5, but competing ferro- and antiferromagnetic exchange in 3. © the Partner Organisations 2014.Citation
McDonald, C., Sanz, S., Brechin, E. K., Singh, M. K., Rajaraman, G., Gaynor, D. and Jones, L. F. (2014) High nuclearity Ni(II) cages from hydroxamate ligands, RSC Advances, 4(72), pp. 38182-38191. https://doi.org/10.1039/c4ra06064dPublisher
Royal Society of Chemistry (RSC)Journal
RSC AdvancesType
Journal articleLanguage
enISSN
2046-2069EISSN
2046-2069Sponsors
EKB would like to thank the EPSRC for funding (SS). GR acknowledges financial support from the Government of India through the Department of Science and Technology (SR/S1/IC-41/2010; SR/NM/NS-1119/2011) and generous computational resources from the Indian Institute of Technology-Bombay. MKS thanks the University Grants Commission for a Junior Research Fellowship.ae974a485f413a2113503eed53cd6c53
10.1039/c4ra06064d
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