(I) Zinc complexes as synthetic analogues for carbonic anhydrase and as catalysts for H₂ production and CO₂ functionalization . . .
type: CreativeWork
description: The multidentate alkyl ligand, [Tptm] ([Tptm] = tris(2-pyridylthio)methyl), provides an organometallic counterpart to the more common tripodal ligands, [Tp] ([Tp] = tris(pyrazolyl)hydroborato) and [Tm] ([Tm] = tris(2-mercaptoimidazolyl) hydroborato). A wide range of [Tptm] zinc complexes have been synthesized, enabling a diverse range of both stoichiometric and catalytic chemical transformations including the production of H₂ and the functionalization of CO₂. The [Tptm] ligand has been used to isolate the first mononuclear alkyl zinc hydride complex, [κ³-Tptm]ZnH. The hydride complex may be easily synthesized on a multigram scale via reaction of the trimethylsiloxide complex, [κ⁴-Tptm]ZnOSiMe₃, with PhSiH₃. The hydride complex, [κ³-Tptm]ZnH, provides access to a variety of other [Tptm]ZnX derivatives. For example, [κ³-Tptm]ZnH reacts with (i) R₃SiOH (R = Me, Ph) to give [κ⁴-Tptm]ZnOSiR₃, (ii) Me₃SiX (X = Cl, Br, I) to give [κ⁴-Tptm]ZnX and (iii) CO2 to give the formate complex, [κ⁴-Tptm]ZnO2CH. [κ³-Tptm]ZnH is hydrolyzed to give the dimeric hydroxide complex, {[κ³-Tptm]Zn(μ–OH)}₂, which when treated with CO₂, results in the bicarbonate complex, [κ⁴-Tptm]ZnOCO₂H. The halide complexes, [κ⁴-Tptm]ZnX (X = Cl, Br, I), can be used to synthesize the fluoride complex, [κ⁴-Tptm]ZnF, via treatment with tetrabutylammonium fluoride (TBAF). The bis(trimethylsilyl)amide complex, [κ³-Tptm]ZnN(SiMe₃)₂, which has been prepared directly via the reaction of [Tptm]H with [ZnN(SiMe₃)₂]₂, reacts with CO₂ to give the isocyanate complex, [κ⁴-Tptm]ZnNCO. The formation of the isocyanate complex results from a multistep sequence in which the initial step is insertion of CO₂ into the Zn-N(SiMe₃)₂ bond to give the carbamato derivative, [Tptm]Zn[O2CN(SiMe₃)₂], followed by rearrangement to [κ⁴-Tptm]ZnOSiMe₃ with the expulsion of Me₃SiNCO, which further reacts to give [κ⁴-Tptm]ZnNCO. An important discovery is that the rate of the final metathesis step, to give [κ⁴-Tptm]ZnNCO, is enhanced by CO₂. S…
abstract: The multidentate alkyl ligand, [Tptm] ([Tptm] = tris(2-pyridylthio)methyl), provides an organometallic counterpart to the more common tripodal ligands, [Tp] ([Tp] = tris(pyrazolyl)hydroborato) and [Tm] ([Tm] = tris(2-mercaptoimidazolyl) hydroborato). A wide range of [Tptm] zinc complexes have been synthesized, enabling a diverse range of both stoichiometric and catalytic chemical transformations including the production of H₂ and the functionalization of CO₂. The [Tptm] ligand has been used to isolate the first mononuclear alkyl zinc hydride complex, [κ³-Tptm]ZnH. The hydride complex may be easily synthesized on a multigram scale via reaction of the trimethylsiloxide complex, [κ⁴-Tptm]ZnOSiMe₃, with PhSiH₃. The hydride complex, [κ³-Tptm]ZnH, provides access to a variety of other [Tptm]ZnX derivatives. For example, [κ³-Tptm]ZnH reacts with (i) R₃SiOH (R = Me, Ph) to give [κ⁴-Tptm]ZnOSiR₃, (ii) Me₃SiX (X = Cl, Br, I) to give [κ⁴-Tptm]ZnX and (iii) CO2 to give the formate complex, [κ⁴-Tptm]ZnO2CH. [κ³-Tptm]ZnH is hydrolyzed to give the dimeric hydroxide complex, {[κ³-Tptm]Zn(μ–OH)}₂, which when treated with CO₂, results in the bicarbonate complex, [κ⁴-Tptm]ZnOCO₂H. The halide complexes, [κ⁴-Tptm]ZnX (X = Cl, Br, I), can be used to synthesize the fluoride complex, [κ⁴-Tptm]ZnF, via treatment with tetrabutylammonium fluoride (TBAF). The bis(trimethylsilyl)amide complex, [κ³-Tptm]ZnN(SiMe₃)₂, which has been prepared directly via the reaction of [Tptm]H with [ZnN(SiMe₃)₂]₂, reacts with CO₂ to give the isocyanate complex, [κ⁴-Tptm]ZnNCO. The formation of the isocyanate complex results from a multistep sequence in which the initial step is insertion of CO₂ into the Zn-N(SiMe₃)₂ bond to give the carbamato derivative, [Tptm]Zn[O2CN(SiMe₃)₂], followed by rearrangement to [κ⁴-Tptm]ZnOSiMe₃ with the expulsion of Me₃SiNCO, which further reacts to give [κ⁴-Tptm]ZnNCO. An important discovery is that the rate of the final metathesis step, to give [κ⁴-Tptm]ZnNCO, is enhanced by CO₂. S…
author: Sattler, Wesley Ian
language: English
keywords: Chemistry, Chemistry, Inorganic, Zinc compounds, Carbonic anhydrase, Hydrides, Hydrogen, Carbon dioxide
date published: 2012
date modified: 2026-07-24T01:44:22Z
provider: Columbia University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Columbia University

PropertyValue
property ID: DOI
value: 10.7916/D8HD82TF