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1.
Front Chem ; 9: 687183, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34041226

RESUMEN

Conjugated microporous polymers (CMPs) with robust architectures, facilely tunable pore sizes and large specific surface areas have emerged as an important class of porous materials due to their demonstrated prospects in various fields, e.g. gas storage/separation and heterogeneous catalysis. Herein, two new pyrrole-based CMPs with large specific surface areas and good stabilities were successfully prepared by one-step oxidative self-polycondensation of 1,2,4,5-tetra (pyrrol-2-ly)benzene or 1,3,5-tri (pyrrol-2-ly)benzene, respectively. Interestingly, both CMPs showed very high catalytic activity toward Knoevenagel condensation reaction, which was attributed to the inherent pore channels, high specific surface areas and abundant nitrogen sites within CMPs. Additionally, both CMPs displayed excellent recyclability with negligible degradation after 10 cycles. This work provides new possibilities into designing novel nitrogen-rich high-performance heterogeneous catalysts.

2.
Spectrochim Acta A Mol Biomol Spectrosc ; 140: 96-100, 2015 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-25589391

RESUMEN

The infra-red (IR) spectroscopic data for a series of eleven rare earth double-deckers MIII[Nc(SPh)8]2 (M=Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho and Er) have been collected and systematically investigated. For MIII[Nc(SPh)8]2, typical IR marker bands for the naphthalocyanine anion radical [Nc(SPh)8].- were observed at 1317-1325 cm(-1) as the most intense absorption bands, which can be attributed to the pyrrole stretching. As for Ce[Nc(SPh)8]2, the typical IR marker band was also observed at 1317 cm(-1), which shows that the cerium complex exists as the form of CeIII[Nc(SPh)8]2-[Nc(SPh)8].-. In addition, both the Q-bands of electronic absorption spectra and the typical IR absorption bands of naphthalocyanine radical anion [Nc(SPh)8].- move to the high energy as the decrease of rare earth metal ionic radius. These facts suggest that the π-π electron interaction in these double-deckers becomes stronger along with the lanthanide contraction.


Asunto(s)
Complejos de Coordinación/química , Metales de Tierras Raras/química , Porfirinas/química , Electrones , Pirroles/química , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta
3.
Artículo en Inglés | MEDLINE | ID: mdl-23266690

RESUMEN

The infrared (IR) spectroscopic data for a series of nine mixed rare earth triple-deckers M(2)(III)[TO(OH)PP](Pc)(2)] [M=La···Dy, except Pm, Y and Ho⋯Lu; H(2)Por=5-(4-hydroxyphenyl)-10,15,20-tris(4-octyloxyphenyl)porphyrin, Pc=unsubstituted phthalocyanine] with tervalent rare earths have been collected. For M(2)(III)[TO(OH)PP](Pc)(2)], typical IR marker bands for the unsubstituted phthalocyanine dianion Pc(2-) are strong bands at 1327-1329 cm(-1), and a weak band around 1370-1383 cm(-1). They can be assigned to pyrrole CC stretchings. The absence of Pc(2-) another marker IR band around 1376 cm(-1) demonstrates that the cerium metal ion in the IR spectrum of Ce(2)(III)[TO(OH)PP](Pc)(2)] exists as intermediate valence state between III and IV. The IR spectra of these mixed triple-decker complexes reveal that the frequencies of pyrrole stretching, isoindole breathing, and aza stretchings are decreased sensitive to the rare earth ionic size, and remain basically unchanged along with the lanthanide contraction. These facts indicate that the π-π interactions in these mixed triple-deckers are weaker than those in the double-deckers.


Asunto(s)
Indoles/química , Metales de Tierras Raras/química , Porfirinas/química , Isoindoles/química , Ligandos , Pirroles/química , Espectrofotometría Infrarroja
4.
Artículo en Inglés | MEDLINE | ID: mdl-23220668

RESUMEN

Raman spectroscopic data in the range of 500-1,800 cm(-1) for a series of nine mixed rare earth triple-deckers M(2)[TO(OH)PP](Pc)(2) [M=La…Dy, except Pm; H(2)Por=5-(4-hydroxyphenyl)-10,15,20-tris(4-octyloxyphenyl)porphyrin] have been collected using laser excitation sources emitting at 632.8 nm. Comparison with the Raman spectra of the corresponding bis(phthalocyaninato) and mixed double-decker rare earths reveals that the Raman characteristics of these mixed triple-deckers M(2)(III)[TO(OH)PP](Pc)(2) are dominated by Pc(2-) contributions. There is no obvious band that can be assigned to the [TO(OH)PP](2-) moiety. Under excitation at 632.8 nm, typical Raman marker bands of the phthalocyanine dianions Pc(2-) were observed at 1514-1,526 cm(-1) as medium band, resulting from the coupling of pyrrole CC and aza CN stretchings. For Ce(2)(III-IV)[TO(OH)PP](Pc)(2), a strong band at 1,521 cm(-1) with contribution from both pyrrole CC and aza CN stretches as well as the isoindole stretches was the marker Raman band of Pc(2-). The Raman spectra of these mixed triple-decker complexes reveal that most of the Raman vibrations derived from pyrrole stretching, isoindole breathing, CH bend and aza stretching are decreased sensitive to the rare earth ionic size, and remain basically unchanged along with the lanthanide contraction. These facts indicate that the π-π interactions in these mixed triple-deckers are weaker than those in the double-deckers.


Asunto(s)
Complejos de Coordinación/química , Indoles/química , Metales de Tierras Raras/química , Porfirinas/química , Isoindoles , Espectrometría Raman
5.
Acta Crystallogr C ; 65(Pt 1): m42-4, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19129598

RESUMEN

The novel title complex, {[Cu(3)(C(8)H(3)NO(6))(2)(OH)(2)(H(2)O)(6)].2H(2)O}(n), has a one-dimensional polymeric double chain structure where the three Cu atoms are linked by mu(2)-OH and mu(2)-H(2)O groups, and these trinuclear centres are bridged by two 3-nitrophthalate ligands. The asymmetric unit contains one and a half crystallographically independent Cu atoms (one lying on a centre of inversion), both coordinated by six O atoms and exhibiting distorted octahedral coordination geometries, but with different coordination environments. Each 3-nitrophthalate ligand connects to three Cu atoms through two O atoms of one carboxylate group and one O atom of the nitro group. The remaining carboxylate group is free and is involved in intrachain hydrogen bonds, reinforcing the chain linkage.

6.
Artículo en Inglés | MEDLINE | ID: mdl-16497547

RESUMEN

The infra-red spectroscopic data for a series of 13 homoleptic substituted bis(phthalocyaninato) rare earth complexes with tervalent rare earths M(III)(TBPc)(2) [M=Y, Pr, ..., Lu except La, Ce and Pm; TBPc=dianion of 3(4),12(13),21(22),30(31)-tetra(tert-butyl)-phthalocyanine] have been collected with resolution of 2 cm(-1). Raman spectroscopic properties in the range of 500-1,800 cm(-1) for these double-deckers M(III)(TBPc)(2) have been collected using laser excitation sources emitting at 632.8 nm. Both the IR and Raman spectra for M(III)(TBPc)(2) are more complicated than those of homoleptic bis(phthalocyaninato) rare earth analogues due to the decreased molecular symmetry of these double-decker compounds. For this series, the IR typical marker band of (TBPc)(-) appears as an intense absorption at 1,314-1,319 cm(-1), attributed to the pyrrole stretching. Under excitation at 632.8 nm that is in close resonance with the main Q absorption band of phthalocyanine ligand, typical Raman marker band of the monoanion radical (TBPc)(-) was observed at 1,515-1,530 cm(-1) resulting from aza CN stretching. Both techniques reveal that the frequencies of pyrrole stretching, isoindole breathing and aza stretchings depend on the rare earth ionic size, shifting to higher energy along with the lanthanide contraction due to the increased ring-ring interaction across the series.


Asunto(s)
Indoles/química , Metales de Tierras Raras/química , Espectrofotometría Infrarroja , Espectrometría Raman , Isoindoles , Conformación Molecular
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 63(3): 550-5, 2006 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-16384729

RESUMEN

The infrared (IR) spectroscopic data for a series of 15 rare earth double-deckers M[Pc(MeOPhO)(8)](2) [M=Y, La, ..., Lu, except Pm; H(2)Pc=2, 3, 9, 10, 16, 17, 23, 24-octakis(4-methoxyphenoxy)phthalocyanine] with tervalent rare earths M(III)[Pc(MeOPhO)(8)](2) (M=Y, La, ..., Lu except Ce and Pm) and intermediate-valent cerium Ce[Pc(MeOPhO)(8)](2) have been collected with resolution of 2cm(-1). For M(III)[Pc(MeOPhO)(8)](2), typical IR marker band of the monoradical anion Pc(MeOPhO)(8)(-) shows characteristic absorption band whose frequency linearly varies in the range from 1,313 cm(-1) as a weak band for La[Pc(MeOPhO)(8)](2) to 1,324 cm(-1) as a medium band for Lu[Pc(MeOPhO)(8)](2) along with the decrease of rare earth ionic size. For Ce[Pc(MeOPhO)(8)](2), a weak band at 1,324 cm(-1) with contribution from pyrrole stretching was the marker IR band of phthalocyanine dianion Pc(2-). In conclusion, all the metal size-dependent IR absorptions should be contributed primarily from the vibrations of pyrrole, isoindole stretching, breathing or deformation or aza stretching of the Pc ring.


Asunto(s)
Indoles/química , Metales de Tierras Raras/química , Espectrofotometría Infrarroja/métodos , Absorción , Bromuros/química , Dimerización , Electrones , Iones , Isoindoles , Metales , Modelos Químicos , Compuestos de Potasio/química , Pirroles/química , Espectrofotometría
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 59(14): 3273-86, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14607224

RESUMEN

The infra-red (IR) spectroscopic data for a series of 45 homoleptic unsubstituted and substituted bis(phthalocyaninato) rare earth complexes M(Pc)2 and M(Pc*)2 [M=Y, La...Lu except Pm; H2Pc=phthalocyanine; H2Pc*=2,3,9,10,16,17,24,25-octakis(octyloxy)phthalocyanine (H2OOPc) and 2(3),9(10),16(17),24(25)-tetra(tert-butyl)phthalocyanine (H2TBPc)] have been collected with resolution of 2 cm(-1). The IR spectra for M(Pc)2 and M(OOPc)2 are much simpler than those of M(TBPc)2, revealing the relatively higher symmetry of the former two compounds. For M(Pc)2 the Pc-* marker band at 1312-1323 cm(-1), attributed to the pyrrole stretching, and the isoindole stretching band at 1439-1454 cm(-1) are found to be dependent on the central rare earth size, shifting slightly to the higher energy along with the decrease of rare earth radius. The frequency of the vibration at 876-887 cm(-1) is also dependent on the rare earth ionic size. The metal size-sensitivity of this band and theoretical studies render it possible to re-assign it to the coupling of isoindole deformation and aza vibration. The nature of another metal-sensitive vibration mode at 1110-1116 cm(-1), which was previously assigned to the C-H bending, is now re-assigned as an isoindole breathing mode with some small contribution also from C-H in-plane bending. These assignments are supported by comparative studies of the IR spectra of substituted bis(phthalocyaninato) analogues M(OOPc)2 and M(TBPc)2. By comparison between the IR spectra of unsubstituted and substituted bis(phthalocyaninato) rare earth analogues and according to the IR characteristics of alkyl groups, some characteristic vibrational fundamentals due to the Pc rings and the substituents can be separately identified. In conclusion, all the metal size-dependent IR absorptions are composed primarily of the vibrations of pyrrole or isoindole stretching, breathing or deformation or aza stretching of the Pc ring.


Asunto(s)
Indoles/química , Metales de Tierras Raras/química , Isoindoles , Espectrofotometría Infrarroja
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