Dataset Information

Tellurolate: an effective Te-atom transfer reagent to prepare the triad of group 5 metal bis(tellurides).

ABSTRACT: We show in this work how lithium tellurolate Li(X)nTeCH2SiMe3 (X = THF, n = 1, 1; X = 12-crown-4, n = 2, 2), can serve as an effective Te-atom transfer reagent to all group 5 transition metal halide precursors irrespective of the oxidation state. Mononuclear and bis(telluride) complexes, namely (PNP)M(Te)2 (M = V; Nb, 3; Ta, 4; PNP- = N[2-PiPr2-4-methylphenyl]2), are reported herein including structural and spectroscopic data. Whereas the known complex (PNP)V(Te)2 can be readily prepared from the trivalent precursor (PNP)VCl2, two equiv. of tellurolate, and elemental Te partially solubilized with PMe3, complex 3 can also be similarly obtained following the same procedure but with or without a reductant, Na/NaCl. Complex 4 on the other hand is formed from the addition of four equiv. of tellurolate to (PNP)TaF4. Having access to a triad of (PNP)M(Te)2 systems for group 5 metals has allowed us to compare them using a combination of theory and spectroscopy including Te-L1 edge XANES data.

SUBMITTER: Senthil S

PROVIDER: S-EPMC10631448 | biostudies-literature | 2023 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Tellurolate: an effective Te-atom transfer reagent to prepare the triad of group 5 metal bis(tellurides).

Senthil Shuruthi S Kwon Seongyeon S Kong Richard Y RY MacMillan Samantha N SN Zatsepin Pavel P Gau Michael R MR Carroll Patrick J PJ Baik Mu-Hyun MH Lancaster Kyle M KM Mindiola Daniel J DJ

Chemical science 20231005 43

We show in this work how lithium tellurolate Li(X)nTeCH2SiMe3 (X = THF, n = 1, 1; X = 12-crown-4, n = 2, 2), can serve as an effective Te-atom transfer reagent to all group 5 transition metal halide precursors irrespective of the oxidation state. Mononuclear and bis(telluride) complexes, namely (PNP)M(Te)2 (M = V; Nb, 3; Ta, 4; PNP- = N[2-PiPr2-4-methylphenyl]2), are reported herei ...[more]

PMID: 37969607

Similar Datasets

Project description:Reported herein are thermochemical studies of hydrogen atom transfer (HAT) reactions involving transition metal H-atom donors M(II)LH and oxyl radicals. [Fe(II)(H(2)bip)(3)](2+), [Fe(II)(H(2)bim)(3)](2+), [Co(II)(H(2)bim)(3)](2+), and Ru(II)(acac)(2)(py-imH) [H(2)bip = 2,2'-bi-1,4,5,6-tetrahydropyrimidine, H(2)bim = 2,2'-bi-imidazoline, acac = 2,4-pentandionato, py-imH = 2-(2'-pyridyl)imidazole)] each react with TEMPO (2,2,6,6-tetramethyl-1-piperidinoxyl) or (t)Bu(3)PhO(*) (2,4,6-tri-tert-butylphenoxyl) to give the deprotonated, oxidized metal complex M(III)L and TEMPOH or (t)Bu(3)PhOH. Solution equilibrium measurements for the reaction of [Co(II)(H(2)bim)(3)](2+) with TEMPO show a large, negative ground-state entropy for hydrogen atom transfer, -41 +/- 2 cal mol(-1) K(-1). This is even more negative than the DeltaS(o)(HAT) = -30 +/- 2 cal mol(-1) K(-1) for the two iron complexes and the DeltaS(o)(HAT) for Ru(II)(acac)(2)(py-imH) + TEMPO, 4.9 +/- 1.1 cal mol(-1) K(-1), as reported earlier. Calorimetric measurements quantitatively confirm the enthalpy of reaction for [Fe(II)(H(2)bip)(3)](2+) + TEMPO, thus also confirming DeltaS(o)(HAT). Calorimetry on TEMPOH + (t)Bu(3)PhO(*) gives DeltaH(o)(HAT) = -11.2 +/- 0.5 kcal mol(-1) which matches the enthalpy predicted from the difference in literature solution BDEs. A brief evaluation of the literature thermochemistry of TEMPOH and (t)Bu(3)PhOH supports the common assumption that DeltaS(o)(HAT) approximately 0 for HAT reactions of organic and small gas-phase molecules. However, this assumption does not hold for transition metal based HAT reactions. The trend in magnitude of |DeltaS(o)(HAT)| for reactions with TEMPO, Ru(II)(acac)(2)(py-imH) << [Fe(II)(H(2)bip)(3)](2+) = [Fe(II)(H(2)bim)(3)](2+) < [Co(II)(H(2)bim)(3)](2+), is surprisingly well predicted by the trends for electron transfer half-reaction entropies, DeltaS(o)(ET), in aprotic solvents. This is because both DeltaS(o)(ET) and DeltaS(o)(HAT) have substantial contributions from vibrational entropy, which varies significantly with the metal center involved. The close connection between DeltaS(o)(HAT) and DeltaS(o)(ET) provides an important link between these two fields and provides a starting point from which to predict which HAT systems will have important ground-state entropy effects.

Dataset Information

Tellurolate: an effective Te-atom transfer reagent to prepare the triad of group 5 metal bis(tellurides).

Publications

Tellurolate: an effective Te-atom transfer reagent to prepare the triad of group 5 metal bis(tellurides).

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets