René Gutiérrez-Pérez

New o- and p-methacryloylaminophenylarsonic monomers. Useful building units for water-soluble polymeric and nonlinear optical materials

New o- and p-methacryloylaminophenylarsonic monomers and their sodium salts were prepared from the condensation reaction of o- and p-aminophenylarsonic acids and methacryloyl chloride for obtaining water-soluble cationic exchange polymeric materials by radical polymerization of such monomers. Noteworthy features were the coordination of some metal ions with the o- and p-methacryloylaminophenylarsonic acid (o- and p-MAPHA) monomers by interchange of the corresponding salts and the good nonlinear optical (NLO) properties displayed by these compounds. The structures of the new monomers were determined by mass spectrometry and IR, 1H-NMR, and 13C-NMR spectroscopy.

Reaction of Hydroquinones with Supported Oxidizing Reagents in Solvent-Free Conditions

Abstract Supported MnO2 or HNO3 on bentonitic clay cleanly oxidize some hydroquinones under infrared or microwave irradiation to the corresponding quinones with excellent conversion in short reaction times, using an easy and solvent-free approach.

Synthesis and X-ray characterization of new 1-[μ-dithio-bis-(tricarbonyliron)]-2-(p-R-benzoyl)ethane complexes

Diiron nonacarbonyl reacts with the para- substituted derivatives 1a – d of 3,3-dithio-1-( p -substituted phenyl)-2-propen-1-one affording surprisingly the new dinuclear Fe(0) complexes 2a – d with a σ - S coordination instead of the attended η 2 or η 4 π -coordination upon the α , β -unsaturated system of the ligands. The complexes 2a – c were characterized by mass spectrometry, IR and 1 H- and 13 C-NMR spectroscopies and their structures were fully confirmed by single-crystal X-ray analysis. Such structural studies revealed as the main feature an ideal C 2v (mm 2 ) symmetry with the carbonyl groups in an eclipsed configuration of the Se 2 Fe 2 (CO) 6 moiety.

Reactivity of a two heteroatom stabilized anionic chromium (0) carbene complex towards a mono- and a disubstituted alkyne: New synthesis of γ-aminobutenolides and formation of a novel oligomer chromium (0) complex

Abstract The reaction of the chromium anionic carbene complex 1 towards diphenylacetylene and phenylacetylene is reported. In the former case the synthesis of γ-functionalized butenolides results after demetallation of the chromium complex 2 and the latter leads to the formation of a novel oligomer chromium complex 5. These complexes were characterized by mass spectrometry, IR and 1H and 13C NMR spectroscopies and their structures were confirmed by single-crystal X-ray analysis.

A Modified Procedure for the Preparation of Linear Polyamines

Abstract An efficient method has been developed for obtaining linear polydentate free amines with high purity and yield than the route currently available.

Synthesis and characterization of (R)-(+)-a-methylbenzylmethacryloylamine. A novel and versatile monomer

We synthesized (R)-(+)-α-methylbenzylmethacryloylamine from the condensation reaction of methacryloyl chloride with (R)-(+)-α-methylbenzylamine in order to make a prototype molecule that can mimic some of the necessary characteristics of nonlinear optical (NLO) materials and that could also display potential chiral polymer catalyst properties. The structure of the new monomer (R)-(+)-α-methylbenzylmethacryloylamine along with the formation of the corresponding polymer was determined by NMR and IR spectroscopy.

Reaction of lithium dimethyl cuprate with carbonyl iron alpha,beta-unsaturated ketone complexes: The structure of a novel eta(3),eta(3)-[(1,6-diphenyl)-3,4-(distyr-1-yl)-1,3,5-hexatriene]-Fe(CO)(2) complex

Abstract The reaction between η4-α,β-unsaturated ketene-Fe(CO)3 complexes and Me2CuLi in the absence of CO atmosphere yields the corresponding η4-vinylketene complexes 2, 4 and 6. The reaction between η2-dibenzylideneacetone-Fe(CO)4 and Me2CuLi gives a new dimeric complex 8, which was characterized by mass spectrometry, IR, 1H and 13C NMR spectroscopy and its structure confirmed by single-crystal X-ray analysis.

Synthesis of a new iron tricarbonyl (eta(4))-alpha-pyrone complex by reaction of iron vinyldiketone complexes with methyllithium under a CO atmosphere

Abstract The reaction between a new ( η 4 )- trans -1,2-α,β-unsaturated diketone-Fe(CO) 3 complex derived from trans -1,2-dibenzoylethylene or the corresponding ( η 2 )-Fe(CO) 4 complex with MeLi under a CO atmosphere leads to the formation of an ( η 4 )-α-pyrone-Fe(CO) 3 complex 3 via the respective ( η 4 )-ketene-Fe (O) complex. The structure of the complex was determined by mass spectrometry, IR, 1 H and 13 C NMR spectroscopies and was confirmed by X-ray diffraction studies.

Spectroscopic studies of novel porphyrin-copper(II) and zinc(II) complexes that share the pinch-porphyrin family structure of iron(III) complex models of peroxidases

Six novel pinch-porphyrin complexes [(picdien)(protoporphyrinate dimethyl ester)]copper(II) (7), [(picdien)(mesoporphyrinate dimethyl ester)]copper(II) (8) and [(picdien)(deuteroporphyrinate dimethyl ester)]copper(II) (9), [(picdien)(protoporphyrinate dimethyl ester)]zinc(II) (13), [(picdien)(mesoporphyrinate dimethyl ester)]zinc(II) (14) and [(picdien)(deuteroporphyrinate dimethyl ester)]zinc(II) (15), were prepared from the corresponding free copper(II)-porphyrins (4–6), and zinc(II)-porphyrins (10–12) and picdien (N-(3H-imidazol-4-ylmethyl)-N′-{2-[(3H-imidazol-4-ylmethyl)-amino]-ethyl}-ethane-2,3-diamine). Spectroscopic studies show that complexes (7–9) and (13–15) have the pinch-porphyrin type structure previously found in iron(III) complex models of peroxidases. Complexes (7–9), were characterized by u.v.–vis., m.c.d., and e.s.r. spectroscopy. E.s.r. spectra of the copper parent compounds (4–6) at ca. 10−2–10−4 M concentrations were typical of copper(II)-dimers. The addition of the picdien ligand broke up the dimers as detected by e.s.r. Compounds (7–9) are predominantly monomeric at ca. 10−3 M concentration. The presence of picdien in (7–9) distorts the porphyrin internal portion of the plane so as to make these four internal nitrogen atoms, coordinated to copper(II), e.s.r.-distinguishable. MO and ligand field theories were used to characterize and to evaluate the directional covalence parameters of compounds (7–9). A non-fully axial, out-of-the-porphyrin-plane bonding was found for (7–9), similar to the bonding of the pinch-porphyrins-iron(III). However the in-plane distortion produced by the presence of the picdien ligand on copper(II) is significantly larger than in pinch-porphyrin-iron(III). The n.m.r. data show that the porphyrin-zinc(II) is the less strained and has the weakest bonded structure. The coordination number of the pinch-porphyrin with iron(III), copper(II) and zinc(II), is in all cases six.

X-ray and spectroscopic characterisation of novel mono- and trinuclear Fe(0) complexes derived from 1-dimethylhydrazono-4-phenylbuten-3-ones

Abstract The reaction between α,β-unsaturated derivatives of monohydrazones of 1,2-dicarbonylic compounds (namely the 1-dimethylhydrazono-4-phenylbuten-3-ones (1a–c)) and di-iron nonacarbonyl affords the novel mono- and trinuclear Fe (0) complexes 2b–c and 3a–c, respectively, with a σ-N and an η2-coordination upon the CC bond of the α,β-unsaturated system for the former compounds, which actually generate six-membered metallocycles. With the latter complexes 3a–c, the main structural features are the unexpected presence of a dinuclear iron unit displaying at one end both the σ-N and σ-O coordination and at the other an η2-coordination upon the CN double bond giving rise to an unique organometallic arrangement in the heteroatom-containing moiety and, in addition, an η2-coordination of another Fe(CO)4 fragment upon the CC bond of the α,β-unsaturated system also results. The complexes were characterised by spectroscopic methods (IR, MS, 1H and 13C NMR) and their structures were confirmed by single-crystal X-ray analysis.