Search results for "iTED"

Spectroscopic investigations of matrix effects induced by silicate xerogels prepared by the sol-gel method on the entrapped Cr(NCS) 6 3− ions

1999

Abstract Time- and temperature-resolved electronic absorption end emission spectra of silicate xerogels made via the sol-gel technique and doped with K 3 [Cr(NCS) 6 ] have been obtained. These results, along with excited states lifetime measurements, document an unexpected colour change of the entrapped chromium complex from violet to green. By varying the conditions of the doped xerogels preparation, it has been shown that the observed colour transition can not be attributed to ligand exchange with NH 3 or water molecules. On the other hand, the oxygen-rich network of silicate xerogels might be responsible for the observed behaviour. It has been shown that dimethylsulfoxide (DMSO), while d…

Resonance Raman Studies of Bis(terpyridine)ruthenium(II) Amino Acid Esters and Diesters

2009

Resonance Raman (rR) spectroscopy in combination with DFT calculations was used to elucidate the nature of the 1metal-to-ligand charge-transfer states (1MLCT) of ester derivatives of homo- and heteroleptic bis(terpyridine)ruthenium(II) complexes [RuII(tpy–COOC2H5)(tpy–R)](PF6)2 with R = NH2 (1a), R = COOC2H5 (1b) and R = NHCOCH3 (1c). The rR spectra provide evidence that the 1MLCT states of 1b and 1c are well described by the expected 1[(“t2g”)5{π*(tpy–COOC2H5)}1] electron configuration, while the 1MLCT state of the donor/acceptor-substituted complex 1a also involves the amine-substituted terpyridine ligand. The excited state of 1a can be described by a 1[{dyz/π(tpy–NH2)}1{π*(tpy–COOC2H5)}1…

Combined Theoretical and Experimental Study of the Photophysics of Asulam

2013

The photophysics of the neutral molecular form of the herbicide asulam has been described in a joint experimental and theoretical, at the CASPT2 level, study. The unique π → π* aromatic electronic transition (f, ca. 0.5) shows a weak red-shift as the polarity of the solvent is increased, whereas the fluorescence band undergoes larger red-shifts. Solvatochromic data point to higher dipole moment in the excited state than in the ground state (μ(g)μ(e)). The observed increase in pKa in the excited state (pKa* - pKa, ca. 3) is consistent with the results of the Kamlet-Abboud-Taft and Catalán et al. multiparametric approaches. Fluorescence quantum yield varies with the solvent, higher in water (…

A theoretical insight into the photophysics of psoralen

2006

Psoralen photophysics has been studied on quantum chemistry grounds using the multiconfigurational second-order perturbation method CASPT2. Absorption and emission spectra of the system have been rationalized by computing the energies and properties of the low-lying singlet and triplet excited states. The S1 ππ* state has been determined to be responsible of the lowest absorption and fluorescence bands and to initially carry the population in the photophysical processes related to the phototherapeutic properties of psoralen derivatives. The low-lying T1 ππ* state is, on the other hand, protagonist of the phosphorescence, and its prevalent role in the reactivity of psoralen is suggested to b…

Companies and Company Law in England, 16th to 19th Centuries: Legal Personality, Limited Liability and Pink Unicorns

2020

the contribution explores the early developments of company law in England, from the Sixteenth century onwards, focusing especially on the emergence of the concepts of legal personality and limited liability

Association of ADHD with genetic variants in the 5'-region of the dopamine transporter gene: evidence for allelic heterogeneity.

2008

Contains fulltext : 69953.pdf (Publisher’s version ) (Closed access) Multiple studies have reported an association between attention deficit hyperactivity disorder (ADHD) and the 10-repeat allele of a variable number tandem repeat (VNTR) polymorphism in the 3'-untranslated region (3'UTR) of the dopamine transporter gene (DAT1). Yet, recent meta-analyses of available data find little or no evidence for this association; although there is strong evidence for heterogeneity between datasets. This pattern of findings could arise for several reasons including the presence of relatively rare risk alleles on common haplotype backgrounds or the functional interaction of two or more loci within the g…

Sappho, Hegel and Michael Field: Paradox and desire in lyric III

2021

This article offers a close reading of Katharine Bradley and Edith Cooper’s lyric III in Long Ago, a Sapphic volume of verse published in 1889 under the collaborative nom de plume of Michael Field. This collection articulates a dramatic inquiry into the tragedy of unrequited love in a long cycle of lyrics whose third piece most effectively encapsulates the kernel of what the Fields reconstruct as Sappho’s ambivalent eroticism. The outcome of this reconstruction, as analysed in light of lyric III, is a consistent Hegelian view of desire that subsumes a complex system of tropes, myths, paradoxes and imaginative strategies under an overarching ideology of desire as a radical experience of appr…

Tunneling luminescence in long lasting afterglow of SrAl 2 O 4 :Eu,Dy

2017

The publication is prepared with the financial support of National Research Programme IMIS2.

Material, mental, and moral progress : American conceptions of civilization in late 19th century studies on "things Chinese and Japanese"

2015

Chemi- and Bioluminescence of Cyclic Peroxides

2018

Bioluminescence is a phenomenon that has fascinated mankind for centuries. Today the phenomenon and its sibling, chemiluminescence, have impacted society with a number of useful applications in fields like analytical chemistry and medicine, just to mention two. In this review, a molecular-orbital perspective is adopted to explain the chemistry behind chemiexcitation in both chemi- and bioluminescence. First, the uncatalyzed thermal dissociation of 1,2-dioxetane is presented and analyzed to explain, for example, the preference for triplet excited product states and increased yield with larger nonreactive substituents. The catalyzed fragmentation reaction and related details are then exemplif…