Detailed magnetic study on the formato-bridged MOFs with anion-tunable magnetic properties

Detailed studies of the structures, magnetic properties and photodimerization of a series of formato-bridged MOFs with the general formula M2(HCOO)3(4,4′-bpe)3(H2O)3(X) (4,4′-bpe = 4,4′-bipyridylethylene, M = Mn (1-X-), X- = ClO4-, NO3-, BF4-, I-, Br-; M = Co (2-X-), X- = ClO4-, NO-3; M = Zn (3-X-), X- = NO3-) were reported. Careful magnetic measurements on an ori- ented single crystal of 1-ClO4- determined the spin-flop magnetic phase diagram and some intrinsic parameters, such as the intralayer coupling J, the anisotropy field HA and the exchange field HE. Different anions can remarkably tune the magnetic properties of 1-X-, especially the critical fields of the spin-flop transition. Compound 2-ClO4- remained paramagnetic down to 2 K.     

Synthesis, crystal structures, and magnetic properties of two three-dimensional octacyanotungstate(IV)- based bimetallic frameworks with 4,4′-bipyridine dioxide (4,4′-dpdo)

The reaction of [HN(n-C4H9)3]3[WV(CN)8]·4H2O, 4,4′-bipyridine dioxide(4,4′-dpdo), and MnCl2·4H2O or CuCl2·2H2O gives two new three-dimensional octacyanometalate-based bimetallic assemblies, {[Mn2 (4,4′-dpdo)(H2O)4] [WIV(CN)8]}·6H2O (1) and {[Cu2(4,4′-dpdo)(H2O)][W(CN)8]}·CH3OH·H2O (2). Compound 1 crystallizes in the orthorhombic system, space group P21212 with cell constants a=10.397(2) -, b= 11.321(2) -, c=12.295(3) - and Z=2, whereas 2 crystallizes in the monoclinic system, space group P21/c with cell con...     

Static field induced magnetic relaxations in dinuclear lanthanide compounds of [phen2Ln2（HCOO）4（HCOO）2-2x（NO3）2x]（1,Ln=Gd and x=0.52; 2, Ln=Er and x=0.90; phen=1,10-phenanthroline）

Two dinuclear lanthanide (Ln) complexes, formulated as [phen2Ln2(HCOO)4(HCOO)2-2x(NO3)2x](1, Ln=Gd and x=0.52; 2, Ln = Er and x = 0.90; phen = 1,10-phenanthroline), were synthesized and characterized. They are isostructural. The dinuclear molecule consists of two Ln 3+ bridged by four formate groups and chelated by phen and formate/nitrate ligands, and the Ln 3+ possesses a coordination environment of distorted tri-capped trigonal prism of LnO 7 N 2 . Both compounds behave as paramagnets between 2 and 300 K, but display two static field induced magnetic relaxation processes. One is slow and of spin-lattice type, and it results from the lifting of Kramer’s degeneracy of the ground-states of both Gd 3+ and Er 3+ , and the other is fast, and it might be spin-spin type.