Nucleophilic substitution by benzodithioate anions

Bonnans-Plaisance, C.; Gressier, J.C.

doi:10.1021/ed065p93

Cited by 3 publications

(4 citation statements)

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“…Synthesis of [NMe 3 Bz]S 2 CR (Bz = CH 2 Ph; R = Me, Et, Bu n or Ph) All [NMe 3 Bz]S 2 CR were prepared by the literature method. 9 Manipulations were performed in a fume cupboard. Carbon disulfide (0.78 g, 0.01 mol) in dry THF (20 mL) was slowly added to the appropriate Grignard reagent (10 mL, 0.01 mol) (cooling with a water bath may be necessary), and the mixture was stirred for 1.5 h. About 20 mL of the solvent was removed using a rotatory evaporator, maintaining the temperature below 25 °C.…”

Section: Methodsmentioning

confidence: 99%

“…Using the literature value of K H = 158.5 dm 3 mol −1 , the concentrations of free HCl and Cl − present in the mixtures have been calculated {henceforth designated [HCl] e and [Cl − ] e }. 9 In the kinetic analysis that follows, it is assumed that HCl 2 − acts as neither acid nor base.…”

Section: à ð3þmentioning

confidence: 99%

“…If proton transfer is rate limiting (k R 2 is slow and k R 3 is fast) the rate law associated with mechanism 2 is that shown in eqn (8). However, if chelate ring-opening is rate-limiting (k R 2 is fast and k R 3 is slow), and D is a steady-state intermediate then the rate law for mechanism 2 is that shown in eqn (9).…”

Section: Mechanismmentioning

confidence: 99%

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Mechanisms and rates of proton transfer to coordinated carboxydithioates: studies on [Ni(S₂CR){PhP(CH₂CH₂PPh₂)₂}]⁺(R = Me, Et, Buⁿor Ph)

et al. 2015

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The complexes [Ni(S2CR)(triphos)]BPh4 (R = Me, Et, Bu(n) or Ph; triphos = PhP{CH2CH2PPh2}2) have been prepared and characterised. X-ray crystallography (for R = Et, Ph, C6H4Me-4, C6H4OMe-4 and C6H4Cl-4) shows that the geometry of the five-coordinate nickel in the cation is best described as distorted trigonal bipyramidal, containing a bidentate carboxydithioate ligand with the two sulfur atoms spanning axial and equatorial sites, the other axial site being occupied by the central phosphorus of triphos. The reactions of [Ni(S2CR)(triphos)](+) with mixtures of HCl and Cl(-) in MeCN to form equilibrium solutions containing [Ni(SH(S)CR)(triphos)](2+) have been studied using stopped-flow spectrophotometry. The kinetics show that proton transfer is slower than the diffusion-controlled limit and involves at least two coupled equilibria. The first step involves the rapid association between [Ni(S2CR)(triphos)](+) and HCl to form the hydrogen-bonded precursor, {[Ni(S2CR)(triphos)](+)HCl} (K) and this is followed by the intramolecular proton transfer (k) to produce [Ni(SH(S)CR)(triphos)](2+). In the reaction of [Ni(S2CMe)(triphos)](+) the rate law is consistent with the carboxydithioate ligand undergoing chelate ring-opening after protonation. It seems likely that chelate ring-opening occurs for all [Ni(S2CR)(triphos)](+), but only with [Ni(S2CMe)(triphos)](+) is the protonation step sufficiently fast that chelate ring-opening is rate-limiting. With all other systems, proton transfer is rate-limiting. DFT calculations indicate that protonation can occur at either sulfur atom, but only protonation at the equatorial sulfur results in chelate ring-opening. The ways in which protonation of either sulfur atom complicates the analyses and interpretation of the kinetics are discussed.

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Section: Methodsmentioning

confidence: 99%

Section: à ð3þmentioning

confidence: 99%

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Mechanisms and rates of proton transfer to coordinated carboxydithioates: studies on [Ni(S₂CR){PhP(CH₂CH₂PPh₂)₂}]⁺(R = Me, Et, Buⁿor Ph)

et al. 2015

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“…Benzyltriphenylphosphonium salts of α-carbonyldithiocarboxylates, [PBnPh 3 ][dtXX], are moderately soluble in methanol and soluble in dichloromethane. The dithiocarboxylate salts forming a stable solution in dichloromethane is surprising as dichloromethane is known to react with NMe 4 + salts of dithiocarboxylates [52], forming the methylene-bis(dithioester). We have observed this reaction at elevated temperatures for [PBnPh 3 ][dtbOMe].…”

Section: Making a Series Of Dithiocarboxylatesmentioning

confidence: 99%

Substituent effects on the UV–visible spectrum and excited electronic states of dithiocarboxylates

Newman

Henry

Madriaga

et al. 2022

Photochem Photobiol Sci

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The absorption spectra of a series of dithiocarboxylates were investigated in the ultraviolet-visible region. Two questions that this study aimed to address were as follows: (1) What transitions give rise to the features in the electronic spectra? And (2) what are the long-and short-range substituent effects on the absorption spectra? A series of 11 dithiocarboxylates were prepared as organic soluble salts. Time-dependent density functional theory (TDDFT) was used to calculate excited state energies and oscillator strengths of electronic transitions. TDDFT at the CAM-B3LYP/def2-TZVPD level of theory predicts two low-energy n → π* transitions and two π → π* transitions at higher energy, consistent with the experimental spectra. This state ordering and density is in contrast to the better studied thiocarbonyls for which only two transitions within the singlet manifold appear in the UV-visible region. For derivatives of dithiobenzoate, the energy of the three lowest energy states are insensitive to changes to substituents para to the dithiocarboxylate group. In contrast, the energy of the highest ππ* state varies by 0.78 eV. This work shows that the results of TDDFT calculations can be used to predict the electronic absorption spectra of dithiocarboxylates, providing a useful tool for designing dithiocarboxylate light absorbers.

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Synthese de polymeres porteurs de dithiobenzoates d'ammonium quaternaire

Gressier

1993

European Polymer Journal

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Nucleophilic substitution by benzodithioate anions

Abstract: The experiment described in this paper has been used to illustrate the Gringnard reaction and nucleophilic substitution.

Cited by 3 publications

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Mechanisms and rates of proton transfer to coordinated carboxydithioates: studies on [Ni(S₂CR){PhP(CH₂CH₂PPh₂)₂}]⁺(R = Me, Et, Buⁿor Ph)

Mechanisms and rates of proton transfer to coordinated carboxydithioates: studies on [Ni(S₂CR){PhP(CH₂CH₂PPh₂)₂}]⁺(R = Me, Et, Buⁿor Ph)

Substituent effects on the UV–visible spectrum and excited electronic states of dithiocarboxylates

Synthese de polymeres porteurs de dithiobenzoates d'ammonium quaternaire

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Nucleophilic substitution by benzodithioate anions

Abstract: The experiment described in this paper has been used to illustrate the Gringnard reaction and nucleophilic substitution.

Cited by 3 publications

References 0 publications

Mechanisms and rates of proton transfer to coordinated carboxydithioates: studies on [Ni(S2CR){PhP(CH2CH2PPh2)2}]+(R = Me, Et, Bunor Ph)

Mechanisms and rates of proton transfer to coordinated carboxydithioates: studies on [Ni(S2CR){PhP(CH2CH2PPh2)2}]+(R = Me, Et, Bunor Ph)

Substituent effects on the UV–visible spectrum and excited electronic states of dithiocarboxylates

Synthese de polymeres porteurs de dithiobenzoates d'ammonium quaternaire

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Mechanisms and rates of proton transfer to coordinated carboxydithioates: studies on [Ni(S₂CR){PhP(CH₂CH₂PPh₂)₂}]⁺(R = Me, Et, Buⁿor Ph)

Mechanisms and rates of proton transfer to coordinated carboxydithioates: studies on [Ni(S₂CR){PhP(CH₂CH₂PPh₂)₂}]⁺(R = Me, Et, Buⁿor Ph)