Environment bismuth

Molybdate-Based Catalysts. The first catalyst commercialized by SOHIO for the propylene ammoxidation process was bismuth phosphomolybdate, Bi9PMoi2052, supported on silica (9). The catalytically active and selective component of the catalyst is bismuth molybdate. In commercial fluid-bed operation, the bismuth molybdate catalyst is supported on silica to provide hardness and attrition resistance in the fluidizing environment. Bismuth molybdate catalysts can be prepared by a coprecipitation procedure using aqueous solutions of bismuth nitrate and ammonium molybdate (10). The catal3ret is produced by drying the precipitate and heat treating the dried particles to crystallize the bismuth molybdate phase. Heat treatment temperature for bismuth molybdate catalysts is generally arovmd 500°C. 

Batteries. Many batteries intended for household use contain mercury or mercury compounds. In the form of red mercuric oxide [21908-53-2] mercury is the cathode material in the mercury—cadmium, mercury—indium—bismuth, and mercury—zinc batteries. In all other mercury batteries, the mercury is amalgamated with the zinc [7440-66-6] anode to deter corrosion and inhibit hydrogen build-up that can cause cell mpture and fire. Discarded batteries represent a primary source of mercury for release into the environment. This industry has been under intense pressure to reduce the amounts of mercury in batteries. Although battery sales have increased greatly, the battery industry has aimounced that reduction in mercury content of batteries has been made and further reductions are expected (3). In fact, by 1992, the battery industry had lowered the mercury content of batteries to 0.025 wt % (3). Use of mercury in film pack batteries for instant cameras was reportedly discontinued in 1988 (3). 

Copper (II), Bismuth (III) and lead (II), ai e important elements in the environment and they have essential roles in different biologieal systems. Lead is widely distributed in nature and exhibits severe deleterious effeets on human [1]. Copper is an essential element for the normal metabolism of many living organisms. Bismuth has been used in medieines for the treatment of helieobaeter pylorie-indueed gastritis [2, 3]. Therefore traee analysis of these elements is important for monitoring their eoneentration in the environment. 

Mass spectrometric studies indicate that smaller molecule derivatives such as Bi(SCMe3)3 are monomeric in the gas phase (33), and the solid-state structure of Bi(SC6H2 6118-2,4,6)0 reveals a pyramidal environment for bismuth [S-Bi-S 90.3(2) to 104.5(2)°] with uniform Bi-S distances [Bi-S 2.554(7) to 2.569(8) A], However, the absence of intermolecular contacts is likely enforced by the steric bulk of the... 

The aryl-substituted derivatives of [Bi(SeC6H2R3-2,4,6)3] (R = Me, Pr, Bu) are the only isolated examples of selenolate complexes. They have been characterized by mp, elemental analysis, NMR spectroscopy, and thermal gravimetric analysis, and the solid-state structure of the isopropyl-substituted derivative reveals a tricoordinate environment for bismuth [Bi-Se 2.630(8)-2.711(8) A Se-Bi-Se 92.3(2)-103.3(2)°], imposed by the steric bulk of the ligands (38). 

See Table III.) Bismuth formate Bi(OOCH)3 is prepared by reacting bismuth oxide with a 40% formic acid solution under reflux conditions (50, 64). The solid-state structure shows three different Bi-0 distance ranges [avg. 2.38, 2.52, and 2.77 A] and all oxygen atoms interacting with bismuth, which occupies a six-coordinate, distorted octahedral environment. The octahedra are linked via the carbon centers re-... 

Obridgmg 2.78(1) A], but also effect a bridge in the homoleptic anion. The cation predictably involves bridging thiourea sulfur atoms [Bi-S 2.909(5) and 3.132(5) A] as well as two terminal thiourea ligands [Bi-S 2.677(5) and 3.152(6) A], In contrast, Bi(CH3COO]3(tu)3 is molecular in the solid state with bismuth in a nine-coordinate environment composed of three bidentate acetate groups [avg. Bi-0 2.509(4) A] and three thiourea sulfur atoms [avg. Bi-S 3.061(2) A] in a fac arrangement. 

Complexes of bismuth chloride with 2 equiv of the AT,AT-substituted dithioxamide ligands of the general formulas [BiCl3 RNHC(S)C(S) NHR 2] (R = Me, Et, Pr, nBu, CH2Ph) likely involve five-membered chelate interactions (123) as demonstrated by the structurally characterized example [BiCl3 EtNHC(S)C(S)NHEt 2] Me2CO, which involves a seven-coordinate pentagonal bipyramidal environment for bismuth (124), with chlorine atoms in axial positions [Bi-Cl 2.635(10) and 2.717(1) A] and one equatorial [Bi-Cl 2.651(12) A] with four sulfur centers [Bi-S 2.818(13)-3.042(12) A],... 

Solid-state structures of two bismuth tartrate complexes reveal a similar asymmetric unit composed of two tartrate ligands on a bismuth center and are distinguished by replacement of a proton in Bi(H3tar)(H2tar) 3H20 (160) with by an ammomium ion in NH4[Bi (H2tar)2(H20)] H20 (161). The nine-coordinate bismuth environments in each structure are very similar, as illustrated in 48, respectively,... 

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