Biomedical subjects
Publications and source records attributed to Anthony V Powell.
Poly[1,4,8,11-tetraazacyclotetradecane(2+) [hepta-mu-sulfido-trisulfidohexaantimony(III)]], {(C10H26N4)[Sb6S10]}n, consists of novel [Sb6S10]2- layers containing Sb2S2, Sb4S4 and Sb7S7 hetero-rings, which are separated by macrocyclic amine molecules. The macrocyclic amine molecules are disordered over two crystallographically distinct positions and are diprotonated in order to balance the charge of the anionic layers.
A new family of antimony sulfides, incorporating the macrocyclic tetramine 1,4,8,11-tetraazacyclotetradecane (cyclam), has been prepared by a hydrothermal method. [C10N4H26][Sb4S7] (1), [Ni(C10N4H24)][Sb4S7] (2), and [Co(C10N4H24)]x[C10N4H26](1-x)[Sb4S7] (0.08 < or = x < or = 0.74) (3) have been characterized by single-crystal X-ray diffraction, elemental analysis, thermogravimetry, and analytical electron microscopy. All three materials possess the same novel three-dimensional Sb4S7(2-) framework, constructed from layers of parallel arrays of Sb4S8(4-) chains stacked at 90 degrees to one another. In 1, doubly protonated macrocyclic cations reside in the channel structure of the antimony-sulfide framework. In 2 and 3, the cyclam acts as a ligand, chelating the divalent transition-metal cation. Analytical and X-ray diffraction data indicate that the level of metal incorporation in 2 is effectively complete, whereas in 3, both metalated and nonmetalated forms of the macrocycle coexist within the structure.
Bis(methylammonium) octaantimony(III) dodecasulfide persulfide, (CH3NH3)2[Sb8S12(S2)], contains pairs of [Sb4S7]2- chains joined through an unusual persulfide bond to create infinite double [Sb8S14]2- chains. The double chains are interlocked by longer Sb...S interactions to form sheets approximately parallel to the (101) crystallographic plane. Methylammonium cations, formed by decomposition of 2-methylpropane-1,2-diamine during the synthesis, are located in large (Sb8S10) hetero-ring apertures created within the double chains.
The first 3-D open-framework TiGaPO complex, constructed from Ti(III)O(6), Ti(IV)O(6), GaO(4), and PO(4) polyhedra, contains pyridinium cations in a 1-D pore network and can be oxidized in air at 543 K with retention of the original framework structure.
Solvothermal synthesis affords access to the first truly three-dimensional antimony-sulfide framework which contains one-dimensional circular channels.
Two new silver-antimony sulfides, [C(2)H(9)N(2)][Ag(2)SbS(3)] (1) and [C(2)H(9)N(2)](2)[Ag(5)Sb(3)S(8)] (2), have been prepared solvothermally in the presence of ethylenediamine and characterized by single-crystal X-ray diffraction, thermogravimetry, and elemental analysis. Compound 1 crystallizes in the space group Pn (a = 6.1781(1) A, b =11.9491(3) A, c = 6.9239(2) A, beta =111.164(1) degrees ) and 2 in the space group Pm (a = 6.2215(2) A, b = 15.7707(7) A, c = 11.6478(5) A, beta = 92.645(2) degrees ). The structure of 1 consists of chains of fused five-membered Ag(2)SbS(2) rings linked to form layers, between which the template molecules reside. Compound 2 contains honeycomb-like sheets of fused silver-antimony-sulfide six-membered rings linked to form double layers. The idealized structure can be considered to be an ordered defect derivative of that of lithium bismuthide, Li(3)Bi, and represents a new solid-state structure type.