Oligomerization and Oxide Formation in Bismuth Aryl Alkoxides:  Synthesis and Characterization of Bi₄(μ₄-O)(μ-OC₆F₅)₆{μ₃-OBi(μ-OC₆F₅)₃}₂(C₆H₅CH₃), Bi₈(μ₄-O)₂(μ₃-O)₂(μ-OC₆F₅)₁₆, Bi₆(μ₃-O)₄(μ₃-OC₆F₅){μ₃-OB

Abstract

Exposing [Bi(OR)3(toluene)]2 (1, R = OC6F5) to different solvents leads to the formation of larger polymetallic bismuth oxo alkoxides via ether elimination/oligomerization reactions. Three different compounds were obtained depending upon the conditions: Bi4(mu 4-O)(mu-OR)6(mu 3-OBi(mu-OR)3)2(C6H5CH3) (2), Bi8(mu 4-O)2(mu 3-O)2(mu 2-OR)16 (3), Bi6(mu 3-O)4(mu 3-OR)(mu 3-OBi(OR)4)3 (4). Compounds 2 and 3 can also be synthesized via an alcoholysis reaction between BiPh3 and ROH in refluxing dichloromethane or chloroform. Related oxo complexes NaBi4(mu 3-O)2(OR)9(THF)2 (5) and Na2Bi4(mu 3-O)2(OR)10(THF)2 (6) were obtained from BiCl3 and NaOR in THF. The synthesis of 1 and Bi(OC6Cl5)3 via salt elimination was successful when performed in toluene as solvent. For compounds 2-6 the single-crystal X-ray structures were determined. Variable-temperature NMR spectra are reported for 2, 3, and 5.

From a Bismuth Oxido Diketonate to a Giant Bismuth Oxido Cluster

“…Three of the seven oxido groups centering the octahedron act as m 4 -bridges to which Bi(hfac) x (x = 3 or 4) arms are attached. This structure directly resembles the oxido alkoxide and oxido silanolate clusters [Bi 6 (m 3 -O) 4 {m 3 -OBi(OR) 4 } 3 (m 3 -OR)] (R = C 6 F 5 , [6] SiMe 3…”

“…Major pathways for introduction of the oxido groups during cluster formation include microhydrolysis, ether elimination, and oxidation. [1c, 4] Several bismuth oxido clusters [Bi m O n ] (3 mÀ2 n)+ with surface capping ligands such as hydroxide, [5] alkoxides, [6] aryl oxides, [7] siloxides, [8] carboxylates, [9] and phosphonates [10] were isolated recently by using solvolytic methods. In addition, a few heterometallic bismuth compounds in which metal atoms are connected through oxido bridges [8b, 11] have also been synthesized by similar approaches.…”

Polynuclear Bismuth‐Oxo Clusters: Insight into the Formation Process of a Metal Oxide

“…Large organic substituents reduce the reactivity, but often to an extent which reduces the potential application of these alkoxides as precursors for the sol-gel process. As a result of steric constraints, polynuclear bismuth-oxo alkoxides such as [Bi 8 (m 4 -O) 2 (m 3 -O) 2 (m-OC 6 F 5 ) 16 ] [23] and [Bi 9 (m 3 -O) 7 (m 3 -OR)(OR) 12 ] (R = C 6 F 5 , 2,6-C 6 H 3 Cl 2 ) [23,31,32] are among the largest bismuth-oxo alkoxides reported to date and the formation of larger aggregates with sterically hindered ligands seems unlikely. Addition of auxiliary ligands is one strategy towards larger multimetallic compounds such as [Bi 8 Ti 8 (sal) 20 (m-OiPr) 8 (OiPr) 8 ] (sal = salicylate), [24] which also show a reduced reactivity of the metal alkoxide bonds.…”

“…The hexanuclear unit A is the most common structural motif reported for bismuth-oxo compounds and is realised in bismuth-oxo(hydroxy) nitrates, [41] bismuth-oxo(hydroxy) perchlorates, [42] bismuth-oxo alkoxides, [23,31,32] and bismuth-oxo carboxylates. [43,44] [Bi 18 (m 3 -O) 12 3 ] in toluene at 4 8C that had been exposed to air moisture.…”

Towards a Structural Understanding of the Anti‐Ulcer and Anti‐Gastritis Drug Bismuth Subsalicylate

“…From Mehrings study [Bi 9 O 7 (OSiMe 3 ) 13 ] was characterized, while [Bi 9 O 7 (OC 6 F 5 ) 13 ] [41,42] and its thf solvate [41] were obtained upon hydrolysis and elimination of bis(pentafluorophenyl) ether from dimeric [Bi(OC 6 F 5 ) 3 -(toluene)] 2 . [42] Apart from the obvious differences in the bonding modes of carboxylate with silanolate and phenolate, these clusters are essentially isostructural with 2 and display relatively high thermodynamic stability.…”