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Papers by Manuel Martinez-Rivera
Journal of Chemical Education, 2008
and keywords Full text (PDF) Links to cited JCE articles Supplement Detailed preparative procedur... more and keywords Full text (PDF) Links to cited JCE articles Supplement Detailed preparative procedure for the students Instructor notes Spectral data
Anuario De Historia Contemporanea, 1977
Historia De La Transicion En Espana Los Inicios Del Proceso Democratizador 2007 Isbn 978 84 9742 713 5 Pags 103 119, 2007
Anuario De Historia Contemporanea, 1979
Revista De Historia Industrial, 2009
2010 9th Ieee Ias International Conference on Industry Applications Induscon 2010, Nov 1, 2010
Contabilidad Y Negocios, Apr 2, 2012
Journal of the Chemical Society Chemical Communications, 1988
Inorganic Chemistry, Apr 8, 2002
The substitution reactions of sulfide by phosphines on Pt(IV) complexes having a cyclometalated i... more The substitution reactions of sulfide by phosphines on Pt(IV) complexes having a cyclometalated imine ligand, two methyl groups in a cis geometrical arrangement, and a halogen and a sulfide as ligands, [Pt (Me) 2 X(CkN)(SR 2 )], have been studied as a function of temperature, solvent, and electronic and steric characteristics of the phosphines, sulfides, X, and CkN. In most of these cases, a limiting dissociative mechanism has been found, where the dissociation of the sulfide ligand corresponds to the rate-determining step. The intermediate species formed behaves as a true pentacoordinated Pt(IV) compound in a steady-state concentration only for the systems with SMe 2 ; for the bulkier SEt 2 and SBzl 2 leaving ligands the rate constants and activation parameters show an important degree of solvent dependence, which correlates with the ability of the solvent to form hydrogen bonds. The X-ray crystal structure of one of the dibenzyl sulfide complexes has been determined, and the geometrical arrangement of the ligands has been determined by NOE NMR measurements at low temperature. The nature of the solvent, imine, sulfide, and halogen ligands produces differences in the reaction rates, which can be quantified very well by the corresponding ∆S q values that move from +48 to −90 J K -1 mol -1 . The reaction on [Pt(Me) 2 F(C 5 CF 4 CHNCH 2 Ph) (SMe 2 )] has been found to take place via a mechanism that depends strongly on the bulkiness of the substituting phosphine. While for PCy 3 the reaction is dissociative, for smaller entering ligands the first associatively activated substitution mechanisms on organometallic Pt(IV) complexes have been established with values of ∆H q and ∆S q in the 28−44 kJ mol -1 and −120 to −83 J K -1 mol -1 ranges. Important intramolecular hydrogen bonding in the starting material can be held responsible for this difference with the remaining systems.
Hiades Revista De Historia De La Enfermeria, 2004
Biblioteca de la Universidad Complutense de Madrid, Base de datos de artículos de revistas, ...
Organometallics, 1993
The bifunctional iminic ligands C $ &H= NCH2 (2-C&X)(X= H... more The bifunctional iminic ligands C $ &H= NCH2 (2-C&X)(X= H, C1, Br) and ArCH= NCH2-CsH5 (Ar= 2, 3, 6-C&F3, 2, 4, 6-C. &F3) react with [Pt2Me&SMe2) 21 to give, via oxidative addition of the CF bonds, platinum (1V) products in which the fluorine ligand and the aryl ...
Anuario Del Instituto De Estudios Zamoranos Florian De Ocampo, 2003
Información del artículo Excavación y documentción del campo de túmulos de la Dehesa de Carpurias... more Información del artículo Excavación y documentción del campo de túmulos de la Dehesa de Carpurias, en Villaferrueña (Zamora).
![Research paper thumbnail of Concurrent NCS? substitution at non-equivalent molybdenum(IV) centres of the incomplete cuboidal aqua ion [Mo3(�3-S)(�-O)(�-S)2(H2O)9]4+](https://attachments.academia-assets.com/44396033/thumbnails/1.jpg)
](J Chem Soc Dalton Trans, 1988
The kinetics of NCS-substitution on the unsymmetrical (crystallographically defined) molybdenum(t... more The kinetics of NCS-substitution on the unsymmetrical (crystallographically defined) molybdenum(tv) aqua ion, Mo,SOS,4+, have been studied, under conditions in which substitution is confined to 1 : 1 reaction at each MolV. Biphasic behaviour was observed with first Mo,SOS,4+ ( > 1 O-fold) and then NCS-( > 1 O-fold) in excess, and two equilibration rate constants were obtained. These correspond to concurrent substitution at the molybdenum(iv) centres, t w o of one kind and one of another. A statistical factor of 2 applies to the slower process, which is therefore assigned t o substitution at the two p-0x0 co-ordinated molybdenum( iv) centres. Formation rate constants are 82 and 23 M-' s-' respectively at 25 "C in 2 M HCIO,.
Inorganic Chemistry Communications, 2002
Inorganica Chimica Acta, 2003
The substitution reactions of a series of sulfur, nitrogen and phosphorus-based ligands (L) on Pt... more The substitution reactions of a series of sulfur, nitrogen and phosphorus-based ligands (L) on Pt(IV) complexes having a chloride ligand, the cyclometallated imine ligand C C 5 Cl 4 CHN CH 2 C 6 H 5 , and two methyl groups and the leaving ligand in a mer -geometrical arrangement, [Pt(C ffl N )(CH 3 ) 2 Cl(L)], have been studied as a function of temperature, solvent, and electronic and steric characteristics of the leaving ligands. Although in all cases a limiting dissociative mechanism has been found to apply, where the dissociation of the leaving ligand corresponds to the rate-determining step, the relative values of the different rate constants involved in the process, i.e. dissociation/association of the leaving/entering ligands and the effect of the solvent, change dramatically in the systems studied. The results agree with the previously determined mechanism operating on these substitution reactions, and serve as a very good measure of the strength of the Pt Ã/L bond, which is influenced by both electronic and steric characteristics. The possible solvent-assisted hydrogen bonding of the leaving ligand with the rest of the molecule is made also evident in the relevant situations. The equilibrium constants detected for some of the systems indicate that, although Pt(IV) complexes are expected to be hard acids and prefer nitrogen to sulfur or phosphorus donors, this is not so. This result is in line with the softening of the nature of the Pt(IV) centres of complexes containing several Pt Ã/C bonds. # 2003 Published by Elsevier Science B.V.
Revista De Proteccion Vegetal, 1992
Anuario De Historia Contemporanea, 1980
Journal of Chemical Education, 2008
and keywords Full text (PDF) Links to cited JCE articles Supplement Detailed preparative procedur... more and keywords Full text (PDF) Links to cited JCE articles Supplement Detailed preparative procedure for the students Instructor notes Spectral data
Anuario De Historia Contemporanea, 1977
Historia De La Transicion En Espana Los Inicios Del Proceso Democratizador 2007 Isbn 978 84 9742 713 5 Pags 103 119, 2007
Anuario De Historia Contemporanea, 1979
Revista De Historia Industrial, 2009
2010 9th Ieee Ias International Conference on Industry Applications Induscon 2010, Nov 1, 2010
Contabilidad Y Negocios, Apr 2, 2012
Journal of the Chemical Society Chemical Communications, 1988
Inorganic Chemistry, Apr 8, 2002
The substitution reactions of sulfide by phosphines on Pt(IV) complexes having a cyclometalated i... more The substitution reactions of sulfide by phosphines on Pt(IV) complexes having a cyclometalated imine ligand, two methyl groups in a cis geometrical arrangement, and a halogen and a sulfide as ligands, [Pt (Me) 2 X(CkN)(SR 2 )], have been studied as a function of temperature, solvent, and electronic and steric characteristics of the phosphines, sulfides, X, and CkN. In most of these cases, a limiting dissociative mechanism has been found, where the dissociation of the sulfide ligand corresponds to the rate-determining step. The intermediate species formed behaves as a true pentacoordinated Pt(IV) compound in a steady-state concentration only for the systems with SMe 2 ; for the bulkier SEt 2 and SBzl 2 leaving ligands the rate constants and activation parameters show an important degree of solvent dependence, which correlates with the ability of the solvent to form hydrogen bonds. The X-ray crystal structure of one of the dibenzyl sulfide complexes has been determined, and the geometrical arrangement of the ligands has been determined by NOE NMR measurements at low temperature. The nature of the solvent, imine, sulfide, and halogen ligands produces differences in the reaction rates, which can be quantified very well by the corresponding ∆S q values that move from +48 to −90 J K -1 mol -1 . The reaction on [Pt(Me) 2 F(C 5 CF 4 CHNCH 2 Ph) (SMe 2 )] has been found to take place via a mechanism that depends strongly on the bulkiness of the substituting phosphine. While for PCy 3 the reaction is dissociative, for smaller entering ligands the first associatively activated substitution mechanisms on organometallic Pt(IV) complexes have been established with values of ∆H q and ∆S q in the 28−44 kJ mol -1 and −120 to −83 J K -1 mol -1 ranges. Important intramolecular hydrogen bonding in the starting material can be held responsible for this difference with the remaining systems.
Hiades Revista De Historia De La Enfermeria, 2004
Biblioteca de la Universidad Complutense de Madrid, Base de datos de artículos de revistas, ...
Organometallics, 1993
The bifunctional iminic ligands C $ &H= NCH2 (2-C&X)(X= H... more The bifunctional iminic ligands C $ &H= NCH2 (2-C&X)(X= H, C1, Br) and ArCH= NCH2-CsH5 (Ar= 2, 3, 6-C&F3, 2, 4, 6-C. &F3) react with [Pt2Me&SMe2) 21 to give, via oxidative addition of the CF bonds, platinum (1V) products in which the fluorine ligand and the aryl ...
Anuario Del Instituto De Estudios Zamoranos Florian De Ocampo, 2003
Información del artículo Excavación y documentción del campo de túmulos de la Dehesa de Carpurias... more Información del artículo Excavación y documentción del campo de túmulos de la Dehesa de Carpurias, en Villaferrueña (Zamora).
J Chem Soc Dalton Trans, 1988
The kinetics of NCS-substitution on the unsymmetrical (crystallographically defined) molybdenum(t... more The kinetics of NCS-substitution on the unsymmetrical (crystallographically defined) molybdenum(tv) aqua ion, Mo,SOS,4+, have been studied, under conditions in which substitution is confined to 1 : 1 reaction at each MolV. Biphasic behaviour was observed with first Mo,SOS,4+ ( > 1 O-fold) and then NCS-( > 1 O-fold) in excess, and two equilibration rate constants were obtained. These correspond to concurrent substitution at the molybdenum(iv) centres, t w o of one kind and one of another. A statistical factor of 2 applies to the slower process, which is therefore assigned t o substitution at the two p-0x0 co-ordinated molybdenum( iv) centres. Formation rate constants are 82 and 23 M-' s-' respectively at 25 "C in 2 M HCIO,.
Inorganic Chemistry Communications, 2002
Inorganica Chimica Acta, 2003
The substitution reactions of a series of sulfur, nitrogen and phosphorus-based ligands (L) on Pt... more The substitution reactions of a series of sulfur, nitrogen and phosphorus-based ligands (L) on Pt(IV) complexes having a chloride ligand, the cyclometallated imine ligand C C 5 Cl 4 CHN CH 2 C 6 H 5 , and two methyl groups and the leaving ligand in a mer -geometrical arrangement, [Pt(C ffl N )(CH 3 ) 2 Cl(L)], have been studied as a function of temperature, solvent, and electronic and steric characteristics of the leaving ligands. Although in all cases a limiting dissociative mechanism has been found to apply, where the dissociation of the leaving ligand corresponds to the rate-determining step, the relative values of the different rate constants involved in the process, i.e. dissociation/association of the leaving/entering ligands and the effect of the solvent, change dramatically in the systems studied. The results agree with the previously determined mechanism operating on these substitution reactions, and serve as a very good measure of the strength of the Pt Ã/L bond, which is influenced by both electronic and steric characteristics. The possible solvent-assisted hydrogen bonding of the leaving ligand with the rest of the molecule is made also evident in the relevant situations. The equilibrium constants detected for some of the systems indicate that, although Pt(IV) complexes are expected to be hard acids and prefer nitrogen to sulfur or phosphorus donors, this is not so. This result is in line with the softening of the nature of the Pt(IV) centres of complexes containing several Pt Ã/C bonds. # 2003 Published by Elsevier Science B.V.
Revista De Proteccion Vegetal, 1992
Anuario De Historia Contemporanea, 1980