Zad. Lethbridge et al., Synthesis, structural relationships and magnetic properties of new amine-templated manganese(II) phosphate oxalate framework materials, J CHEM S DA, (12), 2001, pp. 1904-1910
Citations number
22
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS
Three novel three-dimensional framework materials in the manganese(II)-phos
phate-oxalate system have been prepared hydrothermally using organic amines
as structure-directing agents. [H3NC6H10NH3][Mn-2(HPO4)(2)(C2O4)(H2O)(2)]
1 and [H3N(CH2)(2)NH3][Mn-2(HPO4)(2)(C2O4)(H2O)(2)] 2 have related, but not
isomorphous, structures based on layers of vertex-sharing MnO6 and PO4 pol
yhedra linked by bridging oxalate groups. [H3N(CH2)(2)NH3][Mn-4(HPO4)(2)(C2
O4)(3)(H2O)(2)]. 2H(2)O 3 has a very different structure composed of edge-s
haring dimeric MnO6 units linked into chains by PO4 groups, and into a 3-D
framework by oxalate units. 3 can be topotactically dehydrated, with loss o
f both extra-framework and co-ordinated water, to produce a new phase 4. Th
e magnetic susceptibilities of phases 1, 3 and 4 all show Curie-Weiss behav
iour above about 50 K, and a maximum in the susceptibility curve in the vic
inity of 7-12 K, indicating significant antiferromagnetic exchange. Structu
ral relationships to other phosphate-oxalate frameworks are discussed.