Synthetic and structural comparisons of bismuth(iii) carboxylates synthesised under solvent-free and reflux conditions

Abstract

Two synthetic approaches to the formation of bismuth(III) carboxylates have been explored and compared. Ph(3)Bi was reacted with a series of carboxylic acids (RCO(2)H) of varying pK(a) and functionality (R = PhCH[double bond, length as m-dash]CH, o-MeOC(6)H(4), m-MeOC(6)H(4), o-H(2)NC(6)H, o-O(2)NC(6)H(4), p-O(2)NC(6)H(4), 2-(C(5)H(4)N)) under reflux conditions in toluene and solvent-free. The thermochemical profiles of the solvent-free reactions were also studied by DSC-TGA. All reactions produced the tri-substituted bismuth carboxylates in comparable yields and purity with the exceptions of picolinic acid and p-nitrobenzoic acid. 2-Picolinic acid exclusively formed the di-substituted complex, [PhBi(2-(C(5)H(4)N)CO(2))(2)](4), by both methods, while p-nitrobenzoic acid gave the tri-substituted complex through reflux and the di-substituted complex under solvent-free conditions. Two of the complexes were structurally authenticated by single crystal X-ray diffraction: [PhBi(2-(C(5)H(4)N)CO(2))(2)](4) is tetrameric formed through five membered chelate rings involving the pyridyl N and O(-C) rather than the less stable carboxylate (-CO(2)) chelates, while [Bi(o-MeOC(6)H(4)CO(2))(3)](infinity), is a polymer in which dimeric units, constructed around two chelating and one unsymmetrical bridging carboxylate on each Bi centre, are then joined together through longer intermolecular Bi-O bridging bonds.

Anti-Leishmanial activity of homo- and heteroleptic bismuth(III) carboxylates

“…Our previous studies with picolinic acid showed that the bis-carboxylate was the thermodynamically favoured product even if the ratio of acid to BiPh 3 used in the reaction was 3:1 [16]. This was also found for the reaction of 9 with BiPh 3 which, on reflux in methanol (due to better solubility than in ethanol), produced [PhBi(C 9 H 11 N 2 O 3 CO 2 ) 2 (H 2 O)] (21), from either a 2:1 or 3:1 reaction stoichiometry.…”

“…The synthesis and characterisation of tris-carboxylato bismuth(III) complexes derived from naproxen (10), mefenamic acid (11), ketoprofen (12) and diflunisal (13), o-methoxybenzoic acid (14), mmethoxybenzoic acid (15) and o-nitrobenzoic acid (16) are reported elsewhere [15,16]. The new homoleptic tris-substituted complex [Bi {(CH 3 CONH) 2 C 6 H 3 CO 2 } 3 (H 2 O) 3 ] (17) was synthesised from the reaction of 3,5-diacetamidobenzoic acid (8) with BiPh 3 in a 3:1 ratio under reflux in toluene.…”

Synthesis and structural studies of the simplest bismuth(iii) oxo-salicylate complex: [Bi4(μ3-O)2(HO-2-C6H4CO2)8]·2Solv (Solv = MeCN or MeNO2)

“…These distances are similar to the other known bismuth carboxylates. [24][25][26] The solvent to Bi distances are long (3.06(2) Å) for MeCN and 3.103(4) for MeNO 2 ) but the solvents are clearly oriented so that they interact, albeit weakly, with the metal center. We expect the Bi 4 O 2 core will prove to be the simplest bismuth oxo salicylate.…”

A 3-D bismuth–organic framework containing 1-D cationic inorganic [Bi2O2]2+ chains

“…Though the structure is not chiral, it crystallizes in the acentric, orthorhombic space group Fdd2. The correct enantiomorph of the space group was determined by comparison of reflection intensities of Friedel pairs, giving a Flack parameter of 0.033 (14). A value of zero indicates the correct absolute configuration.…”