Synthesis and Structure of a Bismuth(III)/Chromium(VI) Oxo Cluster Containing a Bi₄Cr₄O₁₂Core

Abstract

Bismuth(III) compounds containing the Kläui's oxygen tripodal ligand [CpCo{P(O)(OEt)(2)}(3)](-) (L(OEt)(-)) have been synthesized, and their interactions with dichromate in aqueous media were studied. The treatment of Bi(5)O(OH)(9)(NO(3))(4) with NaL(OEt) in water afforded [L(OEt)Bi(NO(3))(2)](2) (1), whereas that of BiCl(3) with NaL(OEt) in CH(2)Cl(2) yielded L(OEt)BiCl(2) (2). Chloride abstraction of 2 with AgX afforded [L(OEt)BiX(2)](2) [X(-) = triflate (OTf(-)) (3), tosylate (OTs(-)) (4)]. In aqueous solutions at pH > 4, 4 underwent ligand redistribution to give the bis(tripod) complex [(L(OEt))(2)Bi(H(2)O)][OTs] (5). The treatment of 4 with Na(2)Cr(2)O(7) in acetone/water afforded the Bi(III)/Cr(VI) oxo cluster [(L(OEt))(4)Bi(4)(μ(3)-CrO(4))(2)(μ(3)-Cr(2)O(7))(2)] (6) containing a unique Bi(4)Cr(4)O(12) oxometallic core. Compound 6 oxidized benzyl alcohol to give ca. 6 equiv of benzaldehyde. The reaction between 2 and CrO(3) yielded [L(OEt)Bi(OCrO(2)Cl)](2)(μ-Cl)(2) (7). The crystal structures of complexes 4-7 have been determined.

One Ligand, One Metal, Seven Oxidation States: Stable Technetium Complexes with the “Kläui Ligand”

“…Our attempts to isolate the corresponding cationic bis-chelate [Tc­(L OMe ) 2 ] + have failed up to now. Although corresponding compounds are well-known with other trivalent metal ions of cobalt, , manganese, gallium, bismuth, and small lanthanides, , our reactions starting from [TcCl 3 (PPh 3 ) 2 (NCMe)], [TcCl 3 (PMe 2 Ph) 3 ], or [Tc­(thiourea) 3 )]­Cl 3 with an excess of Na­(L OMe ) resulted in the recovery of the starting materials or the formation of dark, unalluring products, from which no crystalline materials could be isolated.…”

Nitrogen, phosphorus, arsenic, antimony and bismuth

“…144 Bisumth(III) complexes containing the cobalt-based tripodal ligand L OEt have been reported. 145 For example, treatment of BiCl 3 with NaL OEt results in the formation of Bi(L OEt )Cl 2 . Oxidation of these species with Na 2 C 2 O 7 generated bismuth-containing chromium-oxide clusters.…”

Synthesis of Spirocyclic Diphosphite-Supported Gold Metallomacrocycles via a Protodeauration/Cyclization Strategy: Mechanistic and Binding Studies

“…8−10 This cobalt-based metalloligand provides an all-oxygen donor environment and has been used to bind a variety of metals including lanthanides and actinides, 11−13 transition metals, 14,15 and main-group elements such as bismuth. 16 Furthermore, there is considerable interest in the preparation of dynamic coordination polymers, metallomacrocycles, and MOFs. 17,18 One approach to the construction of these systems entails the use of both rigid and flexible components.…”

“…With the noteworthy exception of pyrophosphite and its derivatives, , using phosphonates and related compounds to link metal centers through M–P bonds has received less attention and could generate frameworks and architectures with unique geometries and unconventional substrate binding sites. The well-known Kläui ligand is the small-molecule version of this approach. − This cobalt-based metalloligand provides an all-oxygen donor environment and has been used to bind a variety of metals including lanthanides and actinides, − transition metals, , and main-group elements such as bismuth . Furthermore, there is considerable interest in the preparation of dynamic coordination polymers, metallomacrocycles, and MOFs. , One approach to the construction of these systems entails the use of both rigid and flexible components. − Extending this chemistry to well-defined coordination architectures based upon phosphorus-metalated M­[PO 3 R 2 ] fragments has been challenging, partly because of the paucity of precursors.…”