Notni, J. ; Schenk, S. ; Roth, A. ; Plass, W. ; Gorls, H. ; Uhlemann, U. ; Walter, A. ; Schmitt, M. ; Popp, J. ; Chatzipapadopoulos, S. ; Emmler, T. ; Breitzke, H. ; Leppert, J. ; Buntkowsky, G. ; Kempe, K. ; Anders, E. (2006)
Zinc thiolate complexes ZnLn(SR)(+) with azamacrocyclic ligands, part II: Mechanism of the reaction with CS2.
In: European Journal of Inorganic Chemistry, (14)
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The thiolate complexes Zn(15]aneN(4))(S-CH2-C6H5)]ClO4 (1) (15aneN(4) = 1,4,8,12-tetraazacyclopentadecane) and Zn(i-14]aneN(4))(S-CH2-C6H5)ICIO4 (2) (i-14aneN(4) = 1, 4,7, 11 -tetraazacyclotetradecane) have been reacted with carbon disulfide. The trithiocarbonate complexes Zn(15]aneN(4))S-C(S)-S-CH2-C6H5]CIO4 1a, monoclinic, space group P2(1)/n, Z = 8, a = 13,2338(1) angstrom, b = 12.9251(2) angstrom, c = 30.1669(4) angstrom, beta = 101.463(1)degrees, V = 5057.1(1) angstrom(3) and Zn(i14]aneN(4))S-C(S)-S-CH2-C6H5]CIO4 2a, orthorhombic, space group P2(1)2(1)2(1), Z = 8, a = 9.9936(1) angstrom, b 22.1261(4) angstrom, c = 22.3192(4) angstrom, V = 4935.2(l) angstrom(3) were obtained. The reaction of 1 with CS2 is second order with a rate constant of k = (57.6 +/- 2.4) x 10(-3) m(-1.)s(-1) at 25 degrees C. The experimentally determined Eyring activation barrier is Delta H-exp(double dagger) = 65.3 +/- 0.7 kJ(.)mol(-1) (Delta S-exp(double dagger) = -49.9 +/- 2.5 J(.)mol(-1.)K(-1)) and a free energy of activation of Delta G* = 80.2 +/- 1.5 kJ(.)mol(-1) at 25 degrees C. To discriminate between an associative and a dissociative mechanism the barriers for both processes were calculated using density functional theory at the C-PCM(B98/G3MP2Large)//B3LYP/ 6-311+G(d) level. The associative mechanism is clearly favored with a difference in free energies of activation of delta Delta G(double dagger) approximate to 80kJ(.)mol(-1). Its calculated barrier Delta G(theor)(double dagger) = 114.3 kJ(.)mol(-1) is in reasonable agreement with the experimental value. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006).
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2006 |
| Autor(en): | Notni, J. ; Schenk, S. ; Roth, A. ; Plass, W. ; Gorls, H. ; Uhlemann, U. ; Walter, A. ; Schmitt, M. ; Popp, J. ; Chatzipapadopoulos, S. ; Emmler, T. ; Breitzke, H. ; Leppert, J. ; Buntkowsky, G. ; Kempe, K. ; Anders, E. |
| Art des Eintrags: | Bibliographie |
| Titel: | Zinc thiolate complexes ZnLn(SR)(+) with azamacrocyclic ligands, part II: Mechanism of the reaction with CS2 |
| Sprache: | Englisch |
| Publikationsjahr: | 2006 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | European Journal of Inorganic Chemistry |
| (Heft-)Nummer: | 14 |
| URL / URN: | http://apps.webofknowledge.com/full_record.do?product=WOS&se... |
| Kurzbeschreibung (Abstract): | The thiolate complexes Zn(15]aneN(4))(S-CH2-C6H5)]ClO4 (1) (15aneN(4) = 1,4,8,12-tetraazacyclopentadecane) and Zn(i-14]aneN(4))(S-CH2-C6H5)ICIO4 (2) (i-14aneN(4) = 1, 4,7, 11 -tetraazacyclotetradecane) have been reacted with carbon disulfide. The trithiocarbonate complexes Zn(15]aneN(4))S-C(S)-S-CH2-C6H5]CIO4 1a, monoclinic, space group P2(1)/n, Z = 8, a = 13,2338(1) angstrom, b = 12.9251(2) angstrom, c = 30.1669(4) angstrom, beta = 101.463(1)degrees, V = 5057.1(1) angstrom(3) and Zn(i14]aneN(4))S-C(S)-S-CH2-C6H5]CIO4 2a, orthorhombic, space group P2(1)2(1)2(1), Z = 8, a = 9.9936(1) angstrom, b 22.1261(4) angstrom, c = 22.3192(4) angstrom, V = 4935.2(l) angstrom(3) were obtained. The reaction of 1 with CS2 is second order with a rate constant of k = (57.6 +/- 2.4) x 10(-3) m(-1.)s(-1) at 25 degrees C. The experimentally determined Eyring activation barrier is Delta H-exp(double dagger) = 65.3 +/- 0.7 kJ(.)mol(-1) (Delta S-exp(double dagger) = -49.9 +/- 2.5 J(.)mol(-1.)K(-1)) and a free energy of activation of Delta G* = 80.2 +/- 1.5 kJ(.)mol(-1) at 25 degrees C. To discriminate between an associative and a dissociative mechanism the barriers for both processes were calculated using density functional theory at the C-PCM(B98/G3MP2Large)//B3LYP/ 6-311+G(d) level. The associative mechanism is clearly favored with a difference in free energies of activation of delta Delta G(double dagger) approximate to 80kJ(.)mol(-1). Its calculated barrier Delta G(theor)(double dagger) = 114.3 kJ(.)mol(-1) is in reasonable agreement with the experimental value. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006). |
| Freie Schlagworte: | zinc macrocyclic ligands enzyme models heterocumulenes density functional calculations carbonyl sulfide cos density functionals catalytic cycle test set model anhydrase exchange energies consumption gaussian-3 |
| Zusätzliche Informationen: | 067HL Times Cited:10 Cited References Count:37 |
| Fachbereich(e)/-gebiet(e): | 07 Fachbereich Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Physikalische Chemie |
| Hinterlegungsdatum: | 27 Okt 2014 20:47 |
| Letzte Änderung: | 29 Mai 2019 10:46 |
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