We report the synthesis and magnetic characterisation of a series of planar 5) and [Zn 7 (OH) 6 (L 1 ) 6 ](NO 3 ) 2 •3MeNO 2 (6) (where HL 1 = 2-iminomethyl-6methoxy-phenol, HL 2 = 2-iminomethyl-4-bromo-6-methoxy-phenol). Each member exhibits a double-bowl pseudo metallocalix[6]arene topology whereby the individual [M 7 ] units form molecular host cavities which are able to accommodate various guest molecules (MeCN, MeNO 2 and MeOH). Magnetic susceptibility measurements carried out on complexes 1 and 4 indicate weak exchange between the Ni II centres.
The synthesis, structural and magnetic characterisation of a family of Ni(II) cages built from hydroxamate ligands is presented. Two pentanuclear 12-MC Ni(II) -4 metallacrowns [Ni 5 (L 1 ) 4 (MeOH) 4 ](ClO 4 ) 2 $2MeOH (1) and [Ni 5 (L 1 ) 4 (py) 5 ] (ClO 4 phenylhydroxamic acid) share analogous, near-planar {Ni 5 (L 1 ) 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 heptaand nonametallic complexes [Ni 7 (L 1 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 in situ formation and subsequent Cu(ii) ligation of the polydentate pro-ligands o-[(E)-(2-hydroxy-3-methoxyphenyl)methylideneamino]benzohydroxamic acid (L1H3), o-[(E)-(2-hydroxy-3-methoxy-5-bromophenyl)methylideneamino]benzohydroxamic acid (L2H3) and o-[(E)-(2-hydroxyphenyl)methylideneamino]benzohydroxamic acid (L3H3), leads to the self-assembly of the cages [Cu(ii)10(L1)4(2-aph)2(H2O)2](ClO4)4·5MeOH (), [Cu(ii)14(L1)8(MeOH)2.5(H2O)7.5](NO3)4·3MeOH·7H2O (), [Cu(ii)14(L2)8(MeOH)4(H2O)6](NO3)4·6H2O (), [Cu(ii)14(L3)8(MeOH)6(H2O)2](NO3)4·4MeOH·8H2O () and [Cu(ii)30O(OH)4(OMe)2(L1)16(MeOH)4(H2O)2](ClO4)4·2MeOH·30H2O (). Each member comprises a highly unusual topology derived from off-set, stacked, near planar layers of polynuclear subunits connected through long Cu(ii)-O contacts. The exact topology observed is dependent on the specific reaction conditions and methodologies employed. Dc magnetic susceptibility studies on , , and reveals strong antiferromagnetic exchange between the Cu(ii) centres in all siblings. We also present the 1D coordination polymer {[Cu(ii)(L4)]·H2O}n () comprising the pseudo macrocyclic ligand [[2-[(E)-(2-hydroxy-3-methoxy-phenyl)methyleneamino]benzoyl]amino]ethanimidate (L4H2), which is formed upon the incorporation of an MeCN unit at the hydroxamate group of precursor ligand L1H3.
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