Direct Spectroscopic Characterization of a Transitory Dirhodium Donor-Acceptor Carbene Complex

The title compound [systematic name: (R)-(−)-2-acetoxy-2-phenylacetic acid], C10H10O4, is a resolved chiral ester derivative of mandelic acid. The compound contains an acetate group and a carboxylic acid group, which engage in intermolecular hydrogen bonding, forming chains extending parallel to [001] with a short donor–acceptor hydrogen-bonding distance of 2.676 (2) Å.

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Crystallographic and spectroscopic characterization of 4-nitro-2-(trifluoromethyl)benzoic acid and 4-nitro-3-(trifluoromethyl)benzoic acid

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989019003979 ◽

2019 ◽

Vol 75 (4) ◽

pp. 524-528

Author(s):

George L. Diehl III ◽

Lisa Je ◽

Joseph M. Tanski

Keyword(s):

Hydrogen Bonding ◽

Carboxylic Acid ◽

Benzoic Acid ◽

Nitro Group ◽

Spectroscopic Characterization ◽

Acid Group ◽

Carboxylic Acid Group ◽

Donor Acceptor ◽

Graph Set

The title compounds, both C8H4F3NO4, represent two isomers of nitro trifluoromethyl benzoic acid. The compounds each contain a nitro functionality para to the carboxylic acid group, with the trifluoromethyl substituent ortho to the acid group in the 2-isomer and ortho to the nitro group in the 3-isomer. The regiochemistry with respect to the trifluoromethyl group results in steric interactions that rotate the carboxylic acid group or the nitro group out of the aromatic plane in the 2- and 3-isomer, respectively. Each molecule engages in intermolecular hydrogen bonding, forming head-to-tail dimers with graph-set notation R 2 2(8) and donor–acceptor hydrogen-bonding distances of 2.7042 (14) Å in the 2-isomer and 2.6337 (16) in the 3-isomer. Recrystallization attempts did not yield untwinned crystals.

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Spectroscopic Characterization of Ion-Implanted GaN

MRS Proceedings ◽

10.1557/proc-743-l11.35 ◽

2002 ◽

Vol 743 ◽

Cited By ~ 3

Author(s):

L. Chen ◽

B. J. Skromme

Keyword(s):

Low Temperature ◽

High Purity ◽

Spectroscopic Characterization ◽

Acceptor Pair ◽

Donor Acceptor ◽

Optical Activation ◽

Donor Acceptor Pair ◽

Low Temperature Photoluminescence ◽

Do So

ABSTRACTWe investigate implantation of high purity HVPE GaN with Mg, Be, C, Zn, Cd, Ca, N, O, P, As, Ne, and Ar. After annealing at 1300 °C, the material is characterized using low temperature photoluminescence (PL). The Mg acceptors exhibit much better optical activation than Be, C, Zn, Cd, or Ca acceptors implanted and annealed under the same conditions. Acceptor-bound exciton peaks and well-resolved donor-acceptor pair bands are observed for both Mg and Zn. A broad peak centered near 2.78 eV is obtained for Cd, confirming that it is deeper than Zn. Isoelectronic As or P exhibit sharp no-phonon bound exciton lines at 2.952 and 3.200 eV, respectively. Defect-related bands centered at 2.2 and 2.35 eV are studied. Both Be and C strongly enhance the yellow (2.2 eV) PL band, but no other impurities do so, including O.

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Synthesis and Spectroscopic Characterization of Thienopyrazine-Based Fluorophores for Application in Luminescent Solar Concentrators (LSCs)

Molecules ◽

10.3390/molecules26185428 ◽

2021 ◽

Vol 26 (18) ◽

pp. 5428

Author(s):

Xheila Yzeiri ◽

Massimo Calamante ◽

Alessio Dessì ◽

Daniele Franchi ◽

Andrea Pucci ◽

...

Keyword(s):

Stokes Shift ◽

Spectroscopic Characterization ◽

Spectroscopic Studies ◽

Solar Concentrators ◽

Luminescent Solar Concentrators ◽

Silicon Photovoltaics ◽

Donor Acceptor ◽

Intense Light ◽

Stokes Shifts

Organic fluorophores have found broad application as emitters in luminescent solar concentrators (LSCs) for silicon photovoltaics. In particular, the preparation of organic conjugated systems with intense light-harvesting ability, emissions in the deep-red and NIR regions, and large Stokes shift values represent a very challenging undertaking. Here, we report a simple and easy way to prepare three symmetrical donor–acceptor–donor (DAD) organic-emitting materials based on a thienopyrazine core. The central core in the three dyes was modified with the introduction of aromatic substituents, aiming to affect their optical properties. The fluorophores were characterized by spectroscopic studies. In all cases, visible-NIR emissions with large Stokes shifts were found, highlighting these molecules as promising materials for the application in LSCs.

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Single-wall carbon nanotube porphyrin nanoconjugates

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424607000503 ◽

2007 ◽

Vol 11 (06) ◽

pp. 442-447 ◽

Cited By ~ 12

Author(s):

Christian Ehli ◽

Stéphane Campidelli ◽

Fulvio G. Brunetti ◽

Maurizio Prato ◽

Dirk M. Guldi

Keyword(s):

Excited State ◽

Carbon Nanotube ◽

Transient Absorption ◽

Spectroscopic Characterization ◽

Single Wall Carbon Nanotube ◽

Single Wall Carbon ◽

Low Degree ◽

Donor Acceptor ◽

Covalently Linked

We describe the synthesis, microscopic and spectroscopic characterization of a novel donor-acceptor prototype, namely, a single wall carbon nanotube (SWNT) nanoconjugate bearing a covalently linked free base porphyrin ( H 2 P ). In the characterized SWNT- H 2 P nanoconjugate the electronic features of SWNT are largely retained, when compared to pristine SWNT. In fact, carefully controlled reaction conditions lead to a low degree of SWNT functionalization, as evidenced by the preservation of the SWNT van Hove singularities. As a consequence, the overall SWNT loading with H 2 P is so low that in the ground state, the H 2 P features are barely seen, which is different from the excited state, where features of H 2 P are clearly discernable. For example, fluorescence and transient absorption characteristics corroborate, unequivocally, the formation of the H 2 P singlet excited state, which is, however, impacted by the presence of SWNT.

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Synthese, Kristallstruktur und Spektroskopische Charakterisierung des Phosphaniminato-Komplexes [Cl2AlNPCl3]2 und des Phosphanimin-Komplexes [Me3SiNPCl3 · AlCl3]/Synthesis, Crystal Structure, and Spectroscopic Characterization of the Phosphorane Iminato Complex [Cl2AlNPCl3]2, and of the Phosphane Imine Complex [Me3SiNPCl3 · AlCl3]

Zeitschrift für Naturforschung B ◽

10.1515/znb-2002-1107 ◽

2002 ◽

Vol 57 (11) ◽

pp. 1237-1243 ◽

Cited By ~ 1

Author(s):

Britta Jächke ◽

Martin Jansen

Keyword(s):

Crystal Structure ◽

Point Group ◽

Spectroscopic Characterization ◽

Membered Ring ◽

Site Symmetry ◽

X Ray Diffraction ◽

X Ray ◽

Donor Acceptor ◽

New Compounds

Reaction of Me3SiNPCl3 with AlCl3 yields the donor-acceptor complex [Me3SiNPCl3 · AlCl3] (1). Thermal treatment of 1 and simultaneously removing the by-product Me3SiCl results in the formation of [Cl2AlNPCl3]2 (2). Crystallization of 2 from CH2Cl2 yields colorless crystals which have been characterized by single crystal X-ray diffraction analysis (P1̄, a = 719.1(2), b = 843.5(2), c = 857.4(2) pm, α = 64.23(1), β = 76.62(1), γ = 68.21(1)°, Z = 1, R1 = 0.0498). The molecule exhibits site symmetry Ci (point group approximately C2h) and shows as a characteristic feature a planar, almost square Al2N2 four-membered ring with Al-N distances of 187.5(3) and 187.9(3) pm. The phosphorus atoms of the PCl3-groups attached to the nitrogen atoms are almost located in the same plane as defined by the Al2N2-ring. Both new compounds have been characterized by IR, NMR, and MS spectroscopy.

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Crystallographic and spectroscopic characterization of racemic Mosher's Acid

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989020008403 ◽

2020 ◽

Vol 76 (7) ◽

pp. 1143-1145

Author(s):

Carolyn Z. Savich ◽

Joseph M. Tanski

Keyword(s):

Carboxylic Acid ◽

Spectroscopic Characterization ◽

Acid Group ◽

Compound C ◽

Unit Form ◽

Derivatizing Agent ◽

Donor Acceptor ◽

Group A ◽

Mosher’S Acid

The title compound, C10H9F3O3, represents the structure of racemic Mosher's Acid (systematic name: 3,3,3-trifluoro-2-methoxy-2-phenylpropanoic acid), a carboxylic acid that when resolved can be employed as a chiral derivatizing agent. The compound contains a carboxylic acid group, a methoxy group and a trifluoromethyl substituent on an asymmetric benzylic carbon atom. The two independent molecules in the asymmetric unit form a non-centrosymmetric homochiral dimer via intermolecularly hydrogen-bonded head-to-tail dimers with graph-set notation R 2 2(8) and donor–acceptor hydrogen-bonding distances of 2.6616 (13) and 2.6801 (13) Å.

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