Synthetic, structural and solution speciation studies on binary Al(III)-(carboxy)phosphonate systems. Relevance to the neurotoxic potential of Al(III).

Efforts to delineate the interactions of neurotoxic Al(III) with low molecular mass substrates relevant to neurodegenerative processes, led to the investigation of the pH-specific synthetic chemistry of the binary Al(III)-[N-(phosphonomethyl) iminodiacetic acid] (Al-NTAP), Al(III)-[nitrilo-tris(methylene-phosphonic acid)] (Al-NTA3P), and Al(III)-[1-hydroxy ethylidene-1,1-diphosphonic acid] (Al-HEDP) systems, in correlation with solution speciation studies. Reaction of Al(NO(3))(3).9H(2)O with NTAP at pH 7.

Impressive structural diversity and polymorphism in the modular compounds ABi3Q5 (A = Rb, Cs; Q = S, Se, Te).

An outstanding example of structural diversity and complexity is found in the compounds with the general formula ABi(3)Q(5) (A = alkali metal; Q = chalcogen). gamma-RbBi(3)S(5) (I), alpha-RbBi(3)Se(5) (II), beta-RbBi(3)Se(5) (III), gamma-RbBi(3)Se(5) (IV), CsBi(3)Se(5) (V), RbBi(3)Se(4)Te (VI), and RbBi(3)Se(3)Te(2) (VII) were synthesized from A(2)Q (A = Rb, Cs; Q = S, Se) and Bi(2)Q(3) (Q = S, Se or Te) at temperatures above 650 degrees C using appropriate reaction protocols. gamma-RbBi(3)S(5) and alpha-RbBi(3)Se(5) have three-dimensional tunnel structures while the rest of the compounds have lamellar structures.

Computation of aromatic C3N4 networks and synthesis of the molecular precursor N(C3N3)3Cl6.

The successful synthesis and structural characterization of molecules that represent segments of extended solids is a valuable strategy for learning metric and stereochemical characteristics of those solids. This approach has been useful in cases in which the solids are particularly difficult to crystallize and thus their atomic connectivity and overall structures become difficult to deduce with X-ray diffraction techniques. One such class of materials is the covalently linked C(x)N(y) extended solids, where molecular analogues remain largely absent.

Herbicides interacting with lanthanide(III) and calcium(II) ions: structural and biological similarities of Gd and Ca polymers.

In this paper we report the synthesis and characterization of Ca(II), Gd(III) and Ce(III) complexes with chlorophenoxyalkanoic acids, which are commonly used as herbicides. The Gd(III) and Ca(II) complexes were characterized by the typical formulas [Gd(III)(L)(3)(H(2)O)(2).2dmf](n) and [Ca(L)(2)(MeOH)(2)](n) [L=[2,4-D=2,4-dichlorophenoxyacetic acid, 2,4,5-T=2,4,5-trichlorophenoxyacetic acid, MCPA=2-methyl-4-chlorophenoxy acetic acid and 2,4-DP=2-(2,4-dichlorophenoxy)propanoic acid]].

Cs1-xSn1-xBi9+Se15 and Cs1.5-3xBi9.5+xSe15: members of the homologous superseries Am[M1+lSe2+l]2m[M1 + 2l+nSe3 + 3l+n] (A = alkali metal, M = Sn and Bi) allowing structural evolution in three different dimensions.

Cs1-xSn1-xBi9+xSe15 and Cs1.5-3xBi9.5+xSe15 crystallize in a new structure type which does not belong to but is closely related to the members of the homologous series Am[M6-Se8]m[M5+nSe9+n]; the new phases reveal a third dimension of structural evolution for this series according to the formula Am[M1+lSe2+l]2m[M1 + 2l + nSe3 + 3l+n].