resumo
The hydrothermal synthesis and structural characterization of a number of complex compounds containing the divalent tris(oxalato-O,O')germanate anion, [Ge(C(2)O(4))(3)](2-), or the neutral bis(oxalate-O,O')germanium fragment, [Ge(C(2)O(4))(2)], with transition-metal (M) cationic complexes of 1,10'-phenanthroline (phen) is reported: [M(phen)(3)][Ge(C(2)O(4))(3)]center dot xH(2)O [where M(2+) = Cu(2+) (1a and 1b), Fe(2+) (2a and 2b), Ni(2+) (3), Co(2+) (4); x = 0.2 for 2b], [MGe(phen)(2)(mu(2)-OH)(2)(C(2)O(4))(2)] [where M(2+) = Cd(2+) (5) and Cu(2+) (6)]. The isolation of two polymorphs with Cu(2+) (1a and 1b) and other pseudo-polymorphs for Fe(2+) (2a and 2b) was rationalized based on slightly different molar ratios for the starting materials. All compounds have been characterized using EDS, SEM, vibrational spectroscopy (FT-IR and FT-Raman), thermogravimetry, and CHN elemental composition and their structure determined on the basis of single-crystal X-ray diffraction studies. The crystal packing of the different chemical moieties for each series of compounds was discussed on the basis of the various intermolecular interactions present (strong C-H center dot center dot center dot pi and weak C-H center dot center dot center dot O hydrogen-bonding interactions, C-H center dot center dot center dot pi and pi-pi contacts).
palavras-chave
BIMETALLIC CLUSTER COMPLEX; X-RAY-DIFFRACTION; HYDROTHERMAL SYNTHESIS; MAGNETIC-PROPERTIES; CRYSTAL-STRUCTURES; COORDINATION POLYMER; LANTHANIDE OXALATES; POWDER DIFFRACTION; THERMAL-BEHAVIOR; DICHOTOMY METHOD
categoria
Chemistry
autores
Shi, FN; Cunha-Silva, L; Hardie, MJ; Trindade, T; Paz, FAA; Rocha, J
nossos autores
Fa-Nian Shi
Investigador
Filipe Alexandre Almeida Paz
Investigador Principal
João Rocha
Prof. Catedrático