Wolfgang Kiefer

Wolfgang Kiefer
University of Wuerzburg | JMU · Faculty for Chemistry and Pharmacy

Prof. Dr. Dr.h.c.

About

913
Publications
88,035
Reads
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15,914
Citations
Citations since 2016
4 Research Items
3043 Citations
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
Additional affiliations
March 2006 - present
University of Wuerzburg
Position
  • Retired
March 1988 - February 2006
University of Würzburg
Position
  • Full Professor for Physical Chemistry
February 1985 - March 1988
Karl-Franzens-Universität Graz
Position
  • Full Professor for Experimental Physics

Publications

Publications (913)
Article
Full-text available
Free access on JRS website. A summary of this special issue content (4 memorial contributions, 46 contributions including 9 review papers) identifies an snapshot of the use of some of the many facets involving the application of the Raman scattering technique (standard backscattering analysis, use of various exciting wavelengths, femtosecond spectr...
Article
Full-text available
The performance of ultranarrow bandwidth optically pumped semiconductor lasers in Raman spectroscopy is described in this column. Several examples of Raman spectra of liquid and solid samples demonstrate the very successful use of these lasers as excitation sources for high-resolution Raman spectroscopy of samples in the condensed phase.
Article
Full-text available
We have recorded high-resolution polarized and depolarized resonance Raman spectra of molecular iodine with excitation by argon-ion laser lines at 496.5, 488.0, and 476.5 nm up to the seventh, and with 457.9 nm up to the fifth, overtone. These spectra were also calculated numerically applying second-order perturbation theory. In contrast to earlier...
Article
Full-text available
The vapor phase Raman spectra of trimethylene oxide (TMO) and two of its deuterated analogs (α-d2 and β-d2) each show one sharp line on a weak, broad, and unresolved band in the CH2 scissoring region. Under high resolution these lines are resolved into several components. They are assigned to the fundamentals of the scissoring mode of α-CH2 (in-pha...
Article
In this paper we report femtosecond studies of the influence of rare-gas collisions on the dissociation reaction of NaI molecules by investigating the coherent wave packet motion in NaI at a temperature of 670 °C and rare-gas pressures ranging from 0 to 1000 bar. The photodissociation dynamics of NaI is influenced by the interaction between the exc...
Article
A new complex of coumarin-3-carboxylic acid (HCCA) with Pr(III) is synthesized and its structure and molecular properties are investigated by elemental analysis, IR, Raman, NMR measurements and quantum chemical calculations. The elemental analysis suggested the general formula Pr(CCA)2(NO3)(H2O). The HCCA ligand possesses two donor groups (deproton...
Article
Full-text available
Scitation is the online home of leading journals and conference proceedings from AIP Publishing and AIP Member Societies
Article
Conjugate acid–base forms of the drug metoclopramide were investigated by Raman spectroscopy in aqueous solutions and by surface-enhanced Raman scattering (SERS), when the molecules were adsorbed on colloidal silver surfaces. Raman spectra were recorded at pH values below 8, metoclopramide being poorly water soluble at higher pH values. The SERS sp...
Article
Density functional calculations (DFT) by various methods were performed to clarify wavenumber assignments of the experimental observed bands. A comparison with the molecule of uracil was made, and specific scale factors were deduced and employed in the predicted wavenumbers of 5-IU. Comparisons were also performed with other halo-uracil derivatives...
Chapter
Surface-enhanced Raman scattering (SERS) plays an increasingly important role for the selective detection of proteins and nucleic acids, which is usually achieved by labeled antibodies and oligonucleotides. It plays an increasingly important role in this field of biological and biomedical research. Significant advantages of SERS over existing label...
Article
Following the first two reviews on recent advances in linear and non-linear Raman spectroscopy, the present review summarises papers mainly published in the Journal of Raman Spectroscopy during 2008. This again serves to give a brief overview of recent advances in this research field and to provide readers of this journal a quick introduction to th...
Article
Full-text available
We report an experimental study of the first cw solid-state Raman laser operating simultaneously at the frequencies of the first and second Stokes components. Simultaneous generation is ensured by a cavity with an enhanced finesse at both Stokes frequencies. The threshold pump powers for the first (3.4 W) and second (3.67 W) Stokes components sugge...
Article
The solid to smecticG (SmG) phase transition in a Schiff base liquid crystalline compound, terepthal-bis-heptylaniline (TB7A), is monitored in situ by temperature-dependent Raman microspectroscopy, using the band of a CH in-plane bending mode as a marker. Contrary to the earlier report of a sudden wavenumber shift, the in situ measurement shows ver...
Article
Polarized Raman and density functional theory (DFT) approach have been applied to study the static and dynamic properties of pyridazine (PRD) in H2O(W) and D2O(D) environment. The possible hydrogen bonded (HB) complexes of PRD with H2O in gas phase and in the water solvation (using IEF-PCM and Onsager models) have been calculated using a B3LYP func...
Article
Following the first review on recent advances in linear and nonlinear Raman spectroscopy, the present review summarizes papers mainly published in the Journal of Raman Spectroscopy during 2007. This serves to give a fast overview of recent advances in this research field as well as to provide readers of this journal a quick introduction to the vari...
Article
Full-text available
The complexation ability and the binding mode of the ligand coumarin‐3‐carboxylic acid (HCCA) to La(III), Ce(III), Nd(III), Sm(III), Gd(III) and Dy(III) lanthanide ions (Ln(III)) are elucidated at experimental and theoretical level. The complexes were characterized using elemental analysis, DTA and TGA data as well as 1H NMR and 13C NMR spectra. FT...
Article
Precise polarized Raman measurements of 2-chloropyridine (2Clpy) in the region 560–1060 cm−1 and 3-chloropyridine (3Clpy) in the region 680–1080 cm−1 at different concentrations in mole fraction of methanol were made to calculate the isotropic part of the Raman spectra, which has contributions only from vibrational dephasing. A detailed analysis of...
Article
The gadolinium(III) and dysprosium(III) complexes of 3, 5-pyrazoledicarboxylic acid (H3pdc) were synthesized and characterized. The structures of the final complexes were determined by means of FTIR and FTRaman spectral analyses. To help the binding mode elucidation in the new Gd(III) and Dy(III) complexes of h3pdc, detailed vibrational analysis wa...
Article
Abstract— The acridine and phenanthridine hydroperoxides 3 and 7 were synthesized as photochemical hydroxyl radical sources for oxidative DNA damage studies. The generation of hydroxyl radicals upon UVA irradiation (Λ. = 350 nm) was verified by trapping experiments with 5,5-di-methyl-1-pyrroline N-oxide and benzene. The enzymatic assays of the dama...
Article
The application of resonance Raman (RR) and surface-enhanced resonance Raman (SERR) spectroscopies to the qualitative and semiquantitative analysis of the artificial dye indigo carmine has been examined using sodium-citrate-reduced silver colloid and island films with various roughnesses. Additional, the Raman spectrum of the solid state and densit...
Article
Raman spectroscopy has advanced considerably in the last several years due to rapid developments in instrumentation and the availability of theoretical methods for accurate calculation of Raman spectra, thus enormously facilitating the interpretation of Raman data. This review is restricted to cover papers mainly published in the Journal of Raman S...
Article
A concentration-dependent Raman study of the ν(CBr) stretching and trigonal bending modes of 2- and 3-Br-pyridine (2Br-p and 3Br-p) in CH3OH was performed at different mole fractions of the reference molecule, 2Br-p/3Br-p, from 0.1 to 0.9 in order to understand the origin of blue/red wavenumber shifts of the vibrational modes due to hydrogen-bond f...
Article
The complexes of gadolinium(III) and dysprosium(III) were synthesized by reaction of the respective inorganic salts with 3,5-pyrazoledicarboxylic acid in amounts equal to metal to ligand molar ratio of 1 : 2. The structures of the final complexes were determined by means of spectral and elemental analyses. To help further the binding mode elucidati...
Article
FT-IR and FT-Raman spectra of the biomolecule 5-aminouracil were recorded in the regions 400–4000 cm−1 and 10–3500 cm−1, respectively. The observed vibrational wavenumbers were analyzed and assigned to different normal modes of vibration of the molecule. Density functional calculations were performed to support wavenumber assignments of the observe...
Article
FTIR and FT-Raman spectra of 5-bromouracil in the powder form were recorded in the region 400–4000 cm−1 and 50–4000 cm−1, respectively. The observed wavenumbers were analysed and assigned to different normal modes of vibration of the molecule. Quantum chemical calculations were performed to support the assignments of the observed wavenumbers. The p...
Article
Full-text available
The possibility to perform a stimulated Raman adiabatic passage process in molecules on the ultrafast time scale is investigated theoretically. Motivated by recent experiments, the mid R:B<--mid R:X electronic transitions in molecular iodine are studied as a prototype example with the goal to selectively induce a population transfer employing two i...
Article
Raman spectroscopy was used for the study of sodium benzoate, in the solid state, as well in different acid and basic aqueous solutions. The surface-enhanced Raman scattering (SERS) spectra of sodium benzoate solutions in the 4.5-7 pH range were also recorded. Both, Raman and SERS pH dependent spectra reveal the transition of sodium benzoate from t...
Article
The mechanism of ultrafast, coherent Raman transitions driven at high field strengths is explored in theory and experiment. The study addresses the possibility of maintaining control of a vibrational wavepacket that is guided to a desired final state during the course of a Raman excitation by significantly perturbing the participating molecular sta...
Conference Paper
In this report we present the latest data on the development of continuous-wave solid-state Raman lasers and their first application. Data on experimental investigations of Raman conversion in the separate Raman laser (Raman medium is placed between mirrors) are compared with the results on intracavity Raman conversion (Raman medium is placed in th...
Article
The complex of lanthanum(III) was synthesized by reaction of lanthanum(III) nitrate with sodium salt of orotic acid in amounts equal to metal:ligand molar ratio of 1:2. The structure of the final complex was determined by means of vibrational (IR and Raman) spectra and elemental analysis. Significant differences in the IR and Raman spectra of the c...
Article
Sensitive and specific: By using surface-enhanced Raman scattering (SERS) microspectroscopy, solid-phase-bound compounds can be detected directly and marker-free in a few seconds on a single polystyrene bead. No significant contributions of the matrix are observed, as demonstrated by reference Raman spectra.
Article
Empfindlich und spezifisch: Durch oberflächenverstärkte Raman(SERS)-Mikrospektroskopie können festphasengebundene Substanzen direkt und markierungsfrei in wenigen Sekunden auf einzelnen Harzkügelchen detektiert werden. Es wurden keine nennenswerten Beiträge der Matrix detektiert, wie durch den Vergleich mit Referenzspektren belegt wird.
Article
Low wavenumber Raman scattering of the acoustic vibrational modes of nanoparticles was used for the determination of the size distribution of free dielectric and semiconductor nanoparticles and of nanoparticles embedded in matrices. The theoretical background as well as the experimental results for the free noninteracting nanoparticles and for the...
Article
Full-text available
We use high-order Raman scattering in a bulk dielectric to characterize coherent dynamics with precision typical for gas phase experiments. The experimental pump-probe approach allows for the simultaneous observation and separation in space and time of the individual contributions of different-order Raman processes to a coherent wave packet without...
Article
Bis(pyrrol-2-ylmethyleneamine) ligands and their mononuclear monomeric and dinuclear dimeric self-assembly complexes with Cu(II) were investigated by means of IR and Raman spectroscopies and density functional theory. The ground-state geometries were calculated by using the BeckeLeeYangParr composite exchange-correlation functional (B3LYP) and a co...
Article
New complexes of cerium(III) and neodymium(III) with coumarin-3-carboxylic acid (HCCA) were synthesized and characterized. The elemental, DTA and TGA analyses showed the general formula, Ln(CCA)2(NO3)(H2O) (Ln=Ce, Nd). To suggest the binding mode of HCCA a detail vibrational investigation based on Raman, FTIR and DFT/B3LYP/SVP studies of HCCA, its...
Article
The geometry, vibrational wavenumbers, and thermodynamical parameters have been calculated using density functional methods (DFT) for benzonitrile (BN) and the six difluorobenzonitriles (DFBNs) of the series. The results were compared with the available experimental data, and correlations were established for the bond C tbond N and C bond F moietie...
Article
An efficient 1 kHz barium nitrate Raman laser excited with the second harmonic radiation of a lamp pumped Nd:YAG laser has been developed and its characteristics studied. The threshold of the Raman laser generation corresponds to only 0.4 kW of peak pumping power. The laser system generates 15 wavelength components in the 280 800 nm spectral range...
Article
Monosodium glutamate (MSG), a common flavor enhancer, is detected in aqueous solutions by Raman and surface-enhanced Raman (SERS) spectroscopies at the micromolar level. The presence of different species, such as protonated and unprotonated MSG, is demonstrated by concentration and pH dependent Raman and SERS experiments. In particular, the symmetr...
Article
Full-text available
Surface enhanced Raman scattering (SERS) and ATR-FTIR spectroscopy was applied in this work, in order to get information about the adsorption behavior of the title macromolecule with respect to different surfaces. In this case, the silver substrate can be considered as artificial substrate and the investigations regarding the mechanisms of adsorpti...
Article
Full-text available
The complex of La(lll) with coumarin-3-carboxylic acid (HCCA) has been synthesized and characterized with different physicochemical data, elemental analysis, DTA and TGA data, IR, Raman, 1H NMR and 13C NMR spectra. B3LYP method with 6-31G(d) and 6-31++G(d,p) basis sets was successfully applied to study the molecular, electronic and vibrational stru...
Article
Full-text available
The paper discusses a novel sample deposition method and a new substrate for micro-Raman applications, together with some applications for pharmaceutical and fluorescent compound analysis. Teophylline and indigo carmine azo-dye were used as testing molecules. They were able to be detected in trace amounts, compatible with the applications at physio...
Article
UV resonance Raman spectroscopy was applied for a selective enhancement of molecular vibrations of the important antimalarial chloroquine under physiological conditions. The resonance Raman spectra of chloroquine at pH values resembling the pH value of blood and the pH value of the acid food vacuole of plasmodium can unambiguously be distinguished...
Article
The complexes of cerium(III) and neodymium(III) were synthesized by reaction of the respective inorganic salts with 5-aminoorotic acid (H4L) in amounts equal to the metal:ligand molar ratio of 1:3. The structures of the final complexes were determined by means of spectral (IR, Raman, 1H NMR and 13C NMR) and elemental analysis. Significant differenc...
Article
The isotropic part of the Raman bands corresponding to NH2 bending and ν(CO) stretching modes of formamide (HCONH2) at ∼1593 and 1668 cm−1, respectively, in neat HCONH2 as well as in binary mixtures with methanol (CH3OH) were reinvestigated. Variations of their linewidths exclusively with mole fractions of HCONH2, in the range C = 0.1–0.9 were stud...
Article
Ancient coloured glass beads from Sri Lanka and Oman were analysed by Raman microspectroscopy for non-destructive identification of inorganic pigments in the glass. Calcium phosphate (Ca3(PO4)2), cassiterite (SnO2), cuprite (Cu2O) and a Pb(Sn,Si)O3-type lead tin oxide were found to be used as colouring agents. Moreover, a distinction between lead-b...
Article
3,5-Pyrazoledicarboxylic acid was used as a ligand for the synthesis of its Ce(III) and Nd(III) complexes. The complexes of Ce(III) and Nd(III) with 3,5-pyrazoledicarboxylic acid were synthesized and their compositions were determined by elemental analysis. Vibrational study in the solid state of 3,5-pyrazoledicarboxylic acid and its new Ce(III) an...
Article
FT-IR, FT-Raman and electronic absorption spectroscopies were utilized in conjunction with density functional theory (DFT) calculations to investigate the ground and excited states of self-assembled dinuclear dimeric helicates (ZnL)2 and (NiL)2 [L = bis(2,4-dimethyldipyrrin-3-yl)methane]. These studies afford a detailed description of the ground-st...
Article
A Raman study of neat CH3C N and C2H5C N and their binary mixtures (CH3C N + CH3OH) and (C2H5C N + CH3OH) has been made using a scanning multichannel detection technique, which is also more precise, especially when the observed Raman line profile has multiple components. The spectra in the ν(C N) stretching region (2220–2280 cm−1) for both the refe...
Article
The complex of lanthanum (III) was synthesized reacting the respective inorganic salt with 5-aminoorotic acid in amounts equal to the metal:ligand molar ratio of 1:3. The complex was prepared by adding an aqueous solution of lanthanum (III) nitrate to an aqueous solution of the ligand, subsequently raising the pH of the mixture gradually to approx....
Article
The symmetry properties of selected vibrational modes of mesoporphyrin IX dimethyl ester (MP-IX-DME) in solution are investigated under different electronic resonance conditions. The Raman band parameters of the macrocycle modes nu(2), nu(10), nu(11), and nu(19) are determined from a quantitative analysis of polarized spontaneous resonance Raman (R...
Article
Full-text available
We apply Coherent Anti-Stokes Raman Spectroscopy with femtosecond pulses on fast dephasing biomolecular media. We simulate the interaction, compare with the experiments and demonstrate its application as a real time detector for biochemical hazards.
Article
Femtosecond time-resolved two-color four-wave mixing is employed to study the ultrafast excited-state relaxation processes in Ru(tbbpy)+. The relaxation processes leading to a long-lived thermalized 3MLCT-state are found to take place on two distinct time-scales. An ultrafast process, which is attributed to intersystem crossing, rapidly depopulatin...
Chapter
An introduction of the fundamentals of linear and nonlinear Raman spectroscopy is given. The Raman effect is the result of inelastic light scattering. A small amount of the photon energy of the incident light wave is modulated by the molecular scattering system. An energy transfer occurs as a result of the coupling between the incident radiation an...
Article
The lanthanum (III) complex of 5-aminoorotic acid (HAOA) was synthesized and its structure was determined by means of elemental analysis and IR, Raman, and 1H NMR spectroscopies. Significant differences in the IR, Raman, and 1H NMR spectra of the complex were observed as compared to the spectra of the ligand. The geometry of 5-aminoorotic acid was...
Article
Full-text available
Efficient optical parametric amplification of a frequency-upconverted output of a photonic-crystal fiber (PCF) is demonstrated using a double-pass parametric amplifier pumped by 65 mW 150 fs 100 kHz second-harmonic pulses of a Ti:sapphire laser. Such an amplifier provides gain factors in excess of 10 3 for the blueshifted PCF output, gen...
Article
The excited-state processes of protochlorophyllide a, the precursor of chlorophyll a in chlorophyll biosynthesis, are studied using picosecond time-resolved fluorescence spectroscopy. Following excitation into the Soret band, two distinct fluorescence components, with emission maxima at 640 and 647 nm, are observed. The 640 nm emitting component ap...
Article
New types of composite materials belonging to the (100 − x) [50P2O5 · 30CaO · 20Na2O]xAg2O glasses system with 0 ⩽ x ⩽ 0.25 are obtained. Their local structure is analyzed with the help of Raman and infrared spectroscopy and it was found that the glasses structure is built up from predominantly ionic phosphate units. UV–VIS absorption measurements...
Article
The cerium(III) and neodymium(III) complexes of 5-aminoorotic acid were synthesized and characterized by means of spectral data (IR, Raman, 1H NMR and 13C NMR) and elemental analysis. Significant differences in the IR spectra of the complexes were observed as compared with the spectrum of the ligand. A comparative analysis of the Raman spectra of t...
Article
In the present paper we perform a detailed vibrational study of 3,3′-benzylidenebis(4-hydroxycoumarin) (phenyldicoumarol, PhDC) based on both experimental (IR and Raman) and calculated (DFT) vibrational spectra. To help the assignment of the PhDC vibrational modes, the vibrational spectrum of the monomeric building block, 4-hydroxycoumarin (4-HC),...
Article
Geometry, vibrational wavenumbers, and several thermodynamic parameters have been calculated using ab initio quantum chemical methods for the 3-aminobenzonitrile molecule for the first time. The results were compared with experimental values. With the help of specific scaling procedures, the observed vibrational wavenumbers were analyzed and assign...
Article
Full-text available
5-Fluorouracil, an extensively used anticarcinogenic drug, was found to undergo a soft adsorption (i.e., no significant structural changes) on the metal surface of different Ag island films (35, 11, 8.7, and 6.5 nm thick). The 35 nm thick film provided the best SERS signal. The resistance of the Ag-complexed species to washing demonstrates the film...