Manuel Gómez | Universidad de Guanajuato (original) (raw)
Papers by Manuel Gómez
Hui/Bakery Products Science and Technology, 2014
Food Reviews International, 2007
The bakery market is growing due to the development of new technologies related with freezing tem... more The bakery market is growing due to the development of new technologies related with freezing temperatures. In this contribution the state of the art is reviewed, giving special emphasis in the contributions of the last two decades. This review is especially 4 focussing in being a useful guide of the research performed in the application of freezing at different steps of the breadmaking process, giving an overview toward the bakery market is moving on. The raw material requirements, processing conditions and baked bread quality from frozen dough and partially baked bread are reviewed. 8
El Trimestre Económico, 2009
We study the hypothesis of convergence amongst Mexican regions since 1940 with special interest i... more We study the hypothesis of convergence amongst Mexican regions since 1940 with special interest in the post-trade liberalization period. A time-series analysis shows that difference in income levels between the capital and the rest of the regions tend to narrow over time. Using the ...
![Research paper thumbnail of Alkylation, Insertion of Isocyanides, and Intramolecular Rearrangement Processes in Azatantalacyclopentene Complexes. X-ray Crystal Structure of [TaCp*Me 2 (CHCHCMe 2 NAr-κ 2 C , N )] (Cp* = η 5 -C 5 Me 5 ; Ar = 2,6-Me 2 C 6 H 3 ) §](https://attachments.academia-assets.com/47395839/thumbnails/1.jpg)
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Organometallics, 2012
The pseudo-octahedral dichlorido imido hydridotris(3,5-dimethylpyrazolyl)borate niobium and tanta... more The pseudo-octahedral dichlorido imido hydridotris(3,5-dimethylpyrazolyl)borate niobium and tantalum compounds [MTp*Cl 2 (NtBu)] (M = Nb (1a), Ta (1b); Tp* = BH(3,5-Me 2 C 3 HN 2 ) 3 ) were prepared in better yields by treatment of equimolar quantities of MCl 3 (NtBu)py 2 and KTp* in toluene at reflux. Reactions of 1a,b with a small excess of LiNMe 2 (1:1.2 ratio) in toluene gave the corresponding chlorido dimethylamido derivatives [MTp*Cl(NMe 2 )(NtBu)] (M = Nb (2), Ta ). Mixed methyl dimethylamido [MTp*Me-(NMe 2 )(NtBu)] (M = Nb (4), Ta ) complexes were synthesized in good yields by heating for several days a mixture of 2 or 3 and MgClMe, in a 1:1 molar ratio. However, the reactions of 1a,b with excess LiNMe 2 led to bis(dimethylamido) complexes [MTp*(NMe 2 ) 2 (NtBu)] (M = Nb , Ta ) as unitary species. 4 and 5 reacted with B(C 6 F 5 ) 3 to give the cation-like complexes [MTp*(NMe 2 )(NtBu)] + [BMe(C 6 F 5 ) 3 ] − (M = Nb (8), Ta (9)), whereas in the case of complexes 6 and 7 the reaction led to [MTp*(NMe 2 ){N(Me)CH 2 -κ 1 N}(NtBu)] + [BH(C 6 F 5 ) 3 ] − (M = Nb (10), Ta ) derivatives as result of the C−H methyl bond activation into a NMe 2 function. The restricted rotation process of the NMe 2 moiety around the M−N amido bond in complexes 2−7, the pseudo-rotation process of the Tp* ligand into the cationic species 8 and 9, and the CH 2 terminal group around the NCH 2 bond in compounds 10 and 11 were observed and studied by 1 H DNMR spectroscopy. The isomerization of two enantiomers in the mixtures of 4 and 5 with B(C 6 F 5 ) 3 was detected, and their mechanism was proposed. All compounds were studied by IR and multinuclear NMR ( 1 H, 13 C, and 15 N) spectroscopy, and the molecular structures of complexes 1a,b and 3 were determined by X-ray diffraction methods.
European Journal of Inorganic Chemistry, 2009
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Dalton Transactions, 2014
The alkylation of the starting pseudooctahedral dichlorido imido hydridotris(3,5-dimethylpyrazoly... more The alkylation of the starting pseudooctahedral dichlorido imido hydridotris(3,5-dimethylpyrazolyl)borate niobium and tantalum(v) compounds [MTp*Cl2(NtBu)] (M = Nb,Ta; Tp* = BH(3,5-Me2C3HN2)3) with MgClR in different conditions led to new alkyl chlorido imido derivatives [MTp*ClR(NtBu)] (M = Nb/Ta, R = CH2CH31a/1b, CH2Ph 2a/2b, CH2tBu 3a/3b, CH2SiMe34a/4b, CH2CMe2Ph 5a/5b), whereas the dimethyl derivatives [MTp*Me2(NtBu)] (M = Nb 6a, Ta 6b) could be isolated as unitary species when the reaction was carried out using 2 equivalents of the magnesium reagent MgClMe. However, the chlorido methyl [MTp*ClMe(NtBu)] (M = Nb 7a, Ta 7b) complexes were obtained by heating at 50 °C the dichlorido and dimethyl imido complexes mixtures in a 1 : 1 ratio. All of the complexes were studied by multinuclear magnetic resonance spectroscopy and the molecular structures of 1b, 2a/b, 3a/b, 4a and 5a/b were determined by X-ray diffraction methods. In the solid state the complexes 1b, 4a and 5a exhibit only a gauche-anti conformation and the complexes 2a/b, 3a/b and 5b exhibit only a gauche-syn conformation of the alkyl substituents, whereas both conformational states, which do not show mutual exchange in the NMR time scale, were observed for 3a/b in a benzene-d6 solution. The (15)N chemical shifts of the complexes 1-7 are discussed.
Journal of Organometallic Chemistry, 1996
MCp∗ Cl4, () reacts with LiCp (Cp = C5H4(SiMe3)(Cp′); C5H3(SiMe3)2 (Cp″)) and sodium amalgam, in ... more MCp∗ Cl4, () reacts with LiCp (Cp = C5H4(SiMe3)(Cp′); C5H3(SiMe3)2 (Cp″)) and sodium amalgam, in 1:1:1 molar ratio to give the paramagnetic dicyclopentadienyl niobium and tantalum(IV) complexes, MCp∗ CpCl2, (M = Nb, Cp = Cp′ 1; Cp″ 2; M = Ta, Cp = Cp′ 3; Cp″ 4). Reactions of 3 and 4 with equivalent of PCl5 afford the diamagnetic trichlorocomplexes TaCp∗ CpCl3, (Cp = Cp′ 5; Cp″ 6), while oxidation with dry O2 gives the diamagnetic dinuclear complexes [TaCp∗ CpCl2]2(μ-O), (Cp = Cp′ 7; Cp″ 8), and with air are transformed into the corresponding oxoderivatives TaCp∗ CpCl(O), (Cp = Cp′ 9; Cp″ 10). Treatment of compounds 3 and 4 with a slight excess of lithium aluminium hydride affords the trihydrido complexes TaCp∗ CpH3 (Cp = Cp′ 11; Cp″ 12). The trihydrido complex 12 reacts with two-electron donor ligands on heating to yield the hydrido tantalum(III) compounds TaCp∗ Cp″H(L) (L = CO 13, C2H414, RNC 15). All the new complexes were characterized by usual IR and NMR spectroscopic methods. The crystal structures of 3 and 12 were determined by X-ray diffraction studies. Crystals of 3 are orthorhombic, space group P212121, with Z = 4 in a unit cell of dimensions , . Crystals of 12 are triclinic, space group with Z = 2 in a unit cell of dimensions , , α = 75.94(2)°, β = 84.75(3)° and γ = 72.57(4)°. Both structures were solved from diffractometer data by a combination of direct and Fourier methods and refined by full-matrix least squares fit on the basis of 4088 (3) and 4594 (12) observed reflections to R and Rw values of 0.040 and 0.064 (3) and 0.022 and 0.033 (12) respectively.
Hui/Bakery Products Science and Technology, 2014
Food Reviews International, 2007
The bakery market is growing due to the development of new technologies related with freezing tem... more The bakery market is growing due to the development of new technologies related with freezing temperatures. In this contribution the state of the art is reviewed, giving special emphasis in the contributions of the last two decades. This review is especially 4 focussing in being a useful guide of the research performed in the application of freezing at different steps of the breadmaking process, giving an overview toward the bakery market is moving on. The raw material requirements, processing conditions and baked bread quality from frozen dough and partially baked bread are reviewed. 8
El Trimestre Económico, 2009
We study the hypothesis of convergence amongst Mexican regions since 1940 with special interest i... more We study the hypothesis of convergence amongst Mexican regions since 1940 with special interest in the post-trade liberalization period. A time-series analysis shows that difference in income levels between the capital and the rest of the regions tend to narrow over time. Using the ...
Organometallics, 2012
The pseudo-octahedral dichlorido imido hydridotris(3,5-dimethylpyrazolyl)borate niobium and tanta... more The pseudo-octahedral dichlorido imido hydridotris(3,5-dimethylpyrazolyl)borate niobium and tantalum compounds [MTp*Cl 2 (NtBu)] (M = Nb (1a), Ta (1b); Tp* = BH(3,5-Me 2 C 3 HN 2 ) 3 ) were prepared in better yields by treatment of equimolar quantities of MCl 3 (NtBu)py 2 and KTp* in toluene at reflux. Reactions of 1a,b with a small excess of LiNMe 2 (1:1.2 ratio) in toluene gave the corresponding chlorido dimethylamido derivatives [MTp*Cl(NMe 2 )(NtBu)] (M = Nb (2), Ta ). Mixed methyl dimethylamido [MTp*Me-(NMe 2 )(NtBu)] (M = Nb (4), Ta ) complexes were synthesized in good yields by heating for several days a mixture of 2 or 3 and MgClMe, in a 1:1 molar ratio. However, the reactions of 1a,b with excess LiNMe 2 led to bis(dimethylamido) complexes [MTp*(NMe 2 ) 2 (NtBu)] (M = Nb , Ta ) as unitary species. 4 and 5 reacted with B(C 6 F 5 ) 3 to give the cation-like complexes [MTp*(NMe 2 )(NtBu)] + [BMe(C 6 F 5 ) 3 ] − (M = Nb (8), Ta (9)), whereas in the case of complexes 6 and 7 the reaction led to [MTp*(NMe 2 ){N(Me)CH 2 -κ 1 N}(NtBu)] + [BH(C 6 F 5 ) 3 ] − (M = Nb (10), Ta ) derivatives as result of the C−H methyl bond activation into a NMe 2 function. The restricted rotation process of the NMe 2 moiety around the M−N amido bond in complexes 2−7, the pseudo-rotation process of the Tp* ligand into the cationic species 8 and 9, and the CH 2 terminal group around the NCH 2 bond in compounds 10 and 11 were observed and studied by 1 H DNMR spectroscopy. The isomerization of two enantiomers in the mixtures of 4 and 5 with B(C 6 F 5 ) 3 was detected, and their mechanism was proposed. All compounds were studied by IR and multinuclear NMR ( 1 H, 13 C, and 15 N) spectroscopy, and the molecular structures of complexes 1a,b and 3 were determined by X-ray diffraction methods.
European Journal of Inorganic Chemistry, 2009
Skip to Main Content. ...
Dalton Transactions, 2014
The alkylation of the starting pseudooctahedral dichlorido imido hydridotris(3,5-dimethylpyrazoly... more The alkylation of the starting pseudooctahedral dichlorido imido hydridotris(3,5-dimethylpyrazolyl)borate niobium and tantalum(v) compounds [MTp*Cl2(NtBu)] (M = Nb,Ta; Tp* = BH(3,5-Me2C3HN2)3) with MgClR in different conditions led to new alkyl chlorido imido derivatives [MTp*ClR(NtBu)] (M = Nb/Ta, R = CH2CH31a/1b, CH2Ph 2a/2b, CH2tBu 3a/3b, CH2SiMe34a/4b, CH2CMe2Ph 5a/5b), whereas the dimethyl derivatives [MTp*Me2(NtBu)] (M = Nb 6a, Ta 6b) could be isolated as unitary species when the reaction was carried out using 2 equivalents of the magnesium reagent MgClMe. However, the chlorido methyl [MTp*ClMe(NtBu)] (M = Nb 7a, Ta 7b) complexes were obtained by heating at 50 °C the dichlorido and dimethyl imido complexes mixtures in a 1 : 1 ratio. All of the complexes were studied by multinuclear magnetic resonance spectroscopy and the molecular structures of 1b, 2a/b, 3a/b, 4a and 5a/b were determined by X-ray diffraction methods. In the solid state the complexes 1b, 4a and 5a exhibit only a gauche-anti conformation and the complexes 2a/b, 3a/b and 5b exhibit only a gauche-syn conformation of the alkyl substituents, whereas both conformational states, which do not show mutual exchange in the NMR time scale, were observed for 3a/b in a benzene-d6 solution. The (15)N chemical shifts of the complexes 1-7 are discussed.
Journal of Organometallic Chemistry, 1996
MCp∗ Cl4, () reacts with LiCp (Cp = C5H4(SiMe3)(Cp′); C5H3(SiMe3)2 (Cp″)) and sodium amalgam, in ... more MCp∗ Cl4, () reacts with LiCp (Cp = C5H4(SiMe3)(Cp′); C5H3(SiMe3)2 (Cp″)) and sodium amalgam, in 1:1:1 molar ratio to give the paramagnetic dicyclopentadienyl niobium and tantalum(IV) complexes, MCp∗ CpCl2, (M = Nb, Cp = Cp′ 1; Cp″ 2; M = Ta, Cp = Cp′ 3; Cp″ 4). Reactions of 3 and 4 with equivalent of PCl5 afford the diamagnetic trichlorocomplexes TaCp∗ CpCl3, (Cp = Cp′ 5; Cp″ 6), while oxidation with dry O2 gives the diamagnetic dinuclear complexes [TaCp∗ CpCl2]2(μ-O), (Cp = Cp′ 7; Cp″ 8), and with air are transformed into the corresponding oxoderivatives TaCp∗ CpCl(O), (Cp = Cp′ 9; Cp″ 10). Treatment of compounds 3 and 4 with a slight excess of lithium aluminium hydride affords the trihydrido complexes TaCp∗ CpH3 (Cp = Cp′ 11; Cp″ 12). The trihydrido complex 12 reacts with two-electron donor ligands on heating to yield the hydrido tantalum(III) compounds TaCp∗ Cp″H(L) (L = CO 13, C2H414, RNC 15). All the new complexes were characterized by usual IR and NMR spectroscopic methods. The crystal structures of 3 and 12 were determined by X-ray diffraction studies. Crystals of 3 are orthorhombic, space group P212121, with Z = 4 in a unit cell of dimensions , . Crystals of 12 are triclinic, space group with Z = 2 in a unit cell of dimensions , , α = 75.94(2)°, β = 84.75(3)° and γ = 72.57(4)°. Both structures were solved from diffractometer data by a combination of direct and Fourier methods and refined by full-matrix least squares fit on the basis of 4088 (3) and 4594 (12) observed reflections to R and Rw values of 0.040 and 0.064 (3) and 0.022 and 0.033 (12) respectively.