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In the last few years, vibrational spectroscopies have been widely applied in biology and medicine, as a synergic support to commonly used analytical and diagnostic techniques. This review summarizes the relevant researches carried out by using FTIR and Raman spectroscopy on oviparous and mammalian gametes, including human ones.

Fourier-Transform Infrared microspectroscopy, a largely used spectroscopic technique in basic and industrial researches, offers the possibility to analyze the vibrational features of molecular groups within a variety of environments. In the bioclinical field, and, in particular, in the study of cells, tissues and biofluids, it could be considered a supporting objective technique able to characterize the biochemical processes involved in relevant pathologies, such as tumoral diseases, highlighting specific spectral markers associable with the principal biocomponents (proteins, lipids and carbohydrates). In this article, we review the applications of infrared spectroscopy to the study of tumoral diseases of oral cavity compartments with the aim to improve understanding of biological processes involved during the onset of these lesions and to afford to an early diagnosis. Spectral studies on mouth, salivary glands and oral cystic lesions, objectively discriminate normal from dysplastic and cancer states characterizing also the grading.

In the present paper, we compared the histopathological and vibrational analyses of different tissue sections of Oral Squamous Cell Carcinoma (OSCC) at various malignancy grades, in order to unambiguously identify them. To achieve reliable results, healthy and dysplastic samples were also taken into account. FT-IR microspectroscopy is considered an effective tool for studying different molecular structures occurring in tumoral tissues and offers an interesting alternative to detect biochemical changes in a non-subjective way. In particular, on an adequate number of tissue sections affected by three different grades of OSSC (well G1, moderately G2, and poorly G3 differentiated), as well as on dysplastic and healthy tissues (all obtained from surgical resection), the chemical maps were acquired on meaningful areas containing both epithelial and connective structures. The multivariate analysis (Hierarchical Cluster Analysis, HCA, and Principal Component Analysis, PCA), performed separately on epithelial and connective spectral data, afforded to a good segregation for the different morphological structures. By analysing the representative spectra of healthy, dysplastic and tumoral epithelia and connectives, modifications were pin-pointed in the position of bands and absorbance band ratios usually associated with carcinogenesis. Above all, the changes in the protein pattern (with modifications in the length of side chains and in secondary structures), and in carbohydrates and nucleic acids moieties were associated with specific spectral markers of this pathology. The vibrational investigation led to a satisfactory understanding of these lesions so contributing to an early diagnosis, when the sole morphological inspection may result troublesome.

New copper(I) and copper(II) pyrazolate compounds have been prepared by similar synthesis procedures. For the 3,5-NO 2 -pyrazole ligands, the dinuclear cyclic Cu(I) compound [Cu 2 (µ-N,N-3,5-(NO 2 ) 2 pz) 2 (PPh 3 ) 2 ], 1 , was the only compound isolated in high yield, while in the case of the 3,5-bis(trifluoromethyl)-pyrazole ligand a spontaneous rearrangement to the hexanuclear cyclic [trans-Cu 6 (µ-OH) 6 (µ-3,5-(CF 3 ) 2 pz) 6 ], 2 , was observed. The formation of this latter compound ruled out an anion templating mechanism for the synthesis. X-ray diffraction analysis of 1 revealed that the copper cation is in a trigonal environment and involved in a six-membered Cu 2 N 4 core; while the structural analysis of 2 showed that the metal adopts a square-planar geometry, forms five-membered Cu 2 N 2 O rings and ultimately gives rise to a large Cu 6 (N 2 O) 6 crown-type assembly. Compounds 1 and 2 act as very effective homogeneous catalysts towards the neat microwave (MW) assisted peroxidative (with aq. tert-butyl hydroperoxide, TBHP) oxidation of cyclohexane to cyclohexanol and cyclohexanone (total yield up to 58% in 30 min reaction time) via formation of cyclohexyl hydroperoxide (CyOOH) as the primary product.

Melatonin is an important hormone for the synchronization of the reproductive response to appropriate environmental conditions in photoperiodic animals. Even if a large amount of scientific evidences supports its positive impact on oocyte quality and fertilization rate, the biochemical processes involved are not completely understood. Fourier transform infrared (FT-IR) imaging technique has been applied to analyze the variations induced by melatonin administration on both growth and maturation phases of zebrafish oocytes. Chemical maps were acquired on thin ovary sections, from which average spectra were extracted for each class of oocytes. All average spectra were submitted to multivariate analysis, that separated them into different clusters according to oocyte class and treatment. The vibrational analysis highlighted modifications both in the proteic pattern, with an increment in helical structures with respect to β-sheets (amide I and II bands), and in the aliphatic chains and phosphate moieties for oocytes deriving from melatonin treated females. In addition, real time-PCR and enzyme-linked immunosorbent assay (ELISA) analyses showed that the administration of this hormone favoured the synthesis of vitellogenin. The reduction in gene expression involved in preventing oocyte maturation, such as bone morphogenetic protein ( bmp15 ) and transforming growth factor ( tgfβ1 ), was also observed together with the increase of the luteinizing hormone receptor ( lhr ), involved in the induction of oocyte maturation.

The aim of this study was to verify the effects of probiotic Lactobacillus rhamnosus on zebrafish oocyte maturation using FPA (focal plane array) FTIR imaging together with specific biochemical assays (SDS-PAGE, real-time PCR and enzymatic assay). Oocyte growth is prevalently due to a vitellogenic process which consists of the hepatic synthesis of vitellogenin and its selective uptake during maturation. The administration of L. rhamnosus IMC 501 for 10 days induced chemical changes to oocyte composition, promoting the maturation process. Some interesting biochemical features, linked to protein secondary structure (amide I band) and to phospholipidic and glucidic patterns, were detailed by vibrational analysis. The spectro- scopic results were supported by the early increase of the lysosomal enzyme involved in the final oocyte maturation, the cathepsin L. This enzyme increases during follicle maturation, with the highest levels in class IV oocytes. In treated females, class III oocytes showed higher cathepsin L gene expression and enzymatic activity, with levels comparable to class IV oocytes isolated from controls; this can be related to the proteolytic cleavage of the higher molecular mass yolk protein components, as evidenced by SDS-PAGE.

Summary The aim of this manuscript is to study the effects of two different doses of melatonin (100 nm and 1 μm) on fecundity in zebrafish females. In addition, an overview of the mechanisms controlling the energy balance and reproduction in fish was provided. At molecular level the expression of cyclo-oxygenase 2A (Cox2A) gene, involved in ovulation control, Leptin and GHrelin, apparently involved in gonadal proliferation and steroidogenesis control, were evaluated by Real Time PCR in class IIIb oocytes. Besides, melatonin role in metabolic resources regulation was here assessed through FT-IR Spectroscopy. Fecundity was positively affected by both doses of exogenous melatonin and the improvement was associated to the increase of Cox2A gene expression. The improvement of fecundity was concomitant with the increase of Leptin gene expression in class IIIb oocyte, the increase was significantly higher only with the higher dose of melatonin, while a significant increase of GHrelin gene expression was found with the lower dose of melatonin. Moreover, a modulation on carbohydrates and lipids metabolism was observed in muscle tissue after melatonin treatment.

Zebrafish oocytes growth causes relevant modifications in protein components; in fact, the proteolytic cleavage of vitellogenin, a large sex-specific phospholipoglycoprotein synthesized in the female liver, leads to three main yolk protein components (phosphovitin and lipovitellins 1, 2), present as a complex in the oocyte. FT-IR Microspectroscopy could have the potentiality of monitoring these biochemical changes during the maturation process. Representative spectra for I–II, IIIA, IIIB and IV classes oocytes (Hierarchical Clustering Analysis and Principal Component Analysis) were investigated to find specific vibrational patterns corresponding to different maturation degrees. On going from I–II to IV class oocytes, relevant spectral differences were found with III class exhibiting an intermediate spectroscopic behaviour. In particular, the increase of the convoluted band at 2925 cm−1 (CH2 and CH3 stretching modes), as well as of intensity band ratios at 2926/2954 cm−1 (νasym CH2/CH3), 2854/2873 cm−1 (νsym CH2/CH3) and 1452/1392 cm−1 ( δ CH 2 / 3 / ν sym COO - ), suggest longer lipidic chains; broadening of Amide I and II bands and absorptions at 1737 (νC O, phospholipids) and 1157 cm−1 (νC O and νC OH carbohydrates) in lipovitellin and vitellogenin spectra, are present in III and IV classes.

Microimaging Fourier transform infrared spectroscopy is able to monitor differentiation between normal and malignant tissues. All the specimens, previously submitted to histological analysis, displayed abnormal spectra compared with the corresponding normal tissues with changes in many diagnostic bands like those arising from phosphate, C–O and CH stretching vibrational modes. The comparison between cancer (K) and connective (C) spectra evidenced the following differences: in the v CH region 3000–2800 cm −1 no hypomethylation effect was evident in K; the convolution of the bands of connective indicated an expected higher membrane fluidity; in the neoplastic zone, Amide I and II modes showed convoluted bands with maxima at 1651 and 1547 cm −1 , respectively, indicating an α-helix conformation of proteins due to changes in the secondary structure proteins upon carcinogenesis. Other signature bands, such as the deformation O–P–O phosphate band at 965 cm −1 , suggested DNA conformational changes in solid cancer, infiltrating cancer and neoplasia in the region 1350–800 cm −1 . These characteristic bands have been monitored as a function of the degree of cancer progression. Chemometric methods, such as principal component analysis (PCA) and hierarchical clustering analysis (HCA) have been used in order to distinguish spectra of neoplastic and normal zones.

Micro-imaging infrared spectroscopy has been performed on atheromatous plaques in order to localize and characterize substances responsible for the cytotoxic effects that prevent macrophages clearance of lipidic and calcified materials. In plaques with different graded atherosclerotic lesions, infrared determinations allowed to visualize gruel and ceroid toxic components and variously calcified zones. Compare correlations let to visualize the progression of the lesion on going from the lumen to the outer media of the plaque.

FT-IR microimaging was performed on colon tissues with the aim to characterize spectral ‘markers’ to distinguish healthy from pathological tissues. Evidences of spectral peculiarities were mainly found in the finger print region even in the presence of a low grade adenocarcinoma. The occurrence of inflammation and necrotic states can also be demonstrated. Through statistical analysis as well as custom map procedures it was possible to reconstruct the topological distribution of different biochemical states and to verify results from the histopathological analysis. Preliminary results from FT-NIR analysis are in substantial agreement with those in the mid infrared region.

A biomimetic bone-like composite, made of self-assembled collagen fibrils and carbonate hydroxyapatite nanocrystals, has been performed by an electrochemically-assisted deposition on titanium plate. The electrolytic processes have been carried out using a single type I collagen molecules suspension in a diluted Ca(NO3)2 and NH4H2PO4 solution at room temperature and applying a constant current for different periods of time. Using the same electrochemical conditions, carbonate hydroxyapatite nanocrystals or reconstituted collagen fibrils coatings were obtained. The reconstituted collagen fibrils, hydroxyapatite nanocrystals and collagen fibrils/apatite nanocrystals coatings have been characterized chemically, structurally and morphologically, as well as for their ability to bind fibronectin (FN). Fourier Transform Infrared microscopy has been used to map the topographic distribution of the coating components at different times of electrochemical deposition, allowing to single out the individual deposition steps. Moreover, roughness of Ti plate has been found to affect appreciably the nucleation region of the inorganic nanocrystals. Laser scanning confocal microscopy has been used to characterize the FN adsorption pattern on a synthetic biomimetic apatitic phase, which exhibits a higher affinity when it is inter-grown with the collagen fibrils. The results offer auspicious applications in the preparation of medical devices such as biomimetic bone-like compositecoated metallic implants. _ 2007 Elsevier B.V. All rights reserved. Keywords: Hydroxyapatite–collagen coating; Electrochemically-assisted deposition; Micro-imaging FTIR spectroscopy; Laser scanning confocal microscopy; Biomimetic crystal growth; Fibronectin binding

The aim of this study was to determine the effectiveness of polymerization in order to achieve an adequate clinical composite filling. Photopolymerization of new micro matrix restorative resin composite, Esthet-x, shade A3, from Dentsply Corp., was performed with plasma xenon, halogen and light emitting diode (LED) lamps. The degree of conversion (DC) of the resins was determined by means of middle, near infrared and Raman spectroscopy in transmittance and in DRIFT modes. The resin conversion was influenced by the nature of the light source, the distance from the irradiated surface, the exposure time and the depth from the surface. High DC values were obtained with all lamps but they resulted almost constant with the depth only in the LED unit. Micro-hardness and differential thermal analysis were in satisfactory agreement with DC data.

Changes in the biochemistry of oral cavity tissues have been studied by FT-IR microscopy. Various aspects of squamous cell carcinomas of cheek mucosa, of tongue, of gingiva, and of the floor of the mouth have been analyzed through FT-IR imaging with the aim to relate spectral patterns with histopathological results. In particular, changes in frequency and intensity of proteins, connective and nucleic acids vibrational modes as well as the visualization of biochemical single wavenumber or band ratio images allowed a quali- and quantitative evaluation of the changes in the proliferating activity from displastic to neoplastic states. ‘Supervised’ and ‘unsupervised’ procedures of data handling afforded a satisfactory degree of accordance between spectroscopic and histological findings. q 2004 Elsevier B.V. All rights reserved.

Attenuated total reflectance (ATR) microscopy FT-IR and micro-hardness determinations have been used to study defects in polyethylene acetabular cups for hip prosthesis. The morphology of polymer chains and the distribution of crystalline zones can cause anomalous wear, granulomatosis and, consequently, the failure of the implant. The results have been corroborated by applying a structural analysis by means of the finite element method (FEM).

Triple complexes of calf thymus DNA with dimyristoylphosphatidylcholine (DMPC) liposome and bivalent metal ions (Me 2+ ) have been studied by Diffuse Reflectance Fourier Infrared Spectroscopy. By comparing spectra with the ones of the binary systems arising by coupling any two of the three components, more insight on A, B, Z conformational changes in DNA, as well as on chain packing, has been obtained.

The formation of a donor-acceptor complex between tetracyanoethylene and hexamethylbenzene in solid PE films precipitated from chlorobenzene (PE-1) and decane (PE-2) solutions has been investigated. The equilibrium constant of the reaction is higher in PE-2 than in PE-1 and, within the same solvent, in samples precipitated from more concentrated polymer solutions. Sorption measures and IR data show changes in the structure of the amorphous zones of PE after precipitation.

The oxidation of PE precipitated from decane or chlorobenzene was studied in the presence of tetrakis[methylene-3-(3′,5′-di- tert -butyl-4′-hydroxy-phenyl) propionate]methane at 180 °C by measuring the oxygen consumption. The efficiency of the antioxidant is higher on PE precipitated from chlorobenzene than from decane and, in both solvents, from the most diluted solutions. In addition, it has been seen that the decrease of the rate of PE precipitation gives rise to an increase in the stability of the polymer to oxidation. The changes in short-range-order arrangement of the macromolecules during precipitation are discussed.

The vibrational modes of 1-oxyl-2,2′-disubstituted-3-one-indoline and of 1-oxyl-2,2′-disubstituted-3-arylimino-indoline radicals have been attributed and compared with those of a homogeneous series of 3-indolinones. The frequencies and profiles of CO, CN and Witkop bands depend on the nature of the substituent in the 2-position and para to the phenylimino group.

The interactions of metal ions with galactose and xylose have been investigated in the glassy state and in water solutions by comparing the diffuse internal reflectance, cylindrical internal reflectance and transmittance spectra. The nature and amount of the metal ions induce changes in the CC and CO ring, as well as in the skeletal modes.

Infrared determinations on N-acetyl- and N-benzoylaminopyridines in a set and in mixtures of solvents are reported and discussed in terms of bulk and solute-solvent interactions. Contributes from bonded modes have been characterised and attributed. The nature and the position of the substituents on the pyridine ring and the type of environment markedly influence the structural changes.

9-diazo-10-anthrone reacts with RMgX (R = Me, Et, Bu n , 5-hexenyl, Pr i , benzyl, Bu t ) essentially yielding 9-alkylazo-10-hydroxy derivatives, which are isolated in their tautomeric quinoid structure as alkylhydrazones of 9,10-anthraquinone. The yields of these compounds decrease as the oxidation potentials (E ox ) of the Grignards decrease: at the same time additional compounds, formed through a radical mechanism, are obtained in higher yields. The reaction has been interpreted as a competition between single electron transfer (SET) and nucleophilic attack, which occur with ratios varying with the oxidation potentials of the Grignard reagents E'vidences for the SET pathway have been found performing an experiment in the presence of 2,2,6,6-tetramethylpiperidine-l-oxyl (TEMPO) as a scavenger of C-centered radicals.

Complexes of azobisindoles with tetracyanoethylene and tetracyanoquinodimethane were studied by UV-Vis, FT-IR, Raman, NMR and X-ray spectroscopies. FT-IR and Raman spectra, as well as X-ray analysis, gave useful information on the participation of various sites to the association, through analysis of CN and N=N vibrational modes, while UV-Vis and NMR spectra were less helpful. The crystal structure of complexes 1-ethyl-2-phenyl-3-(1-ethyl-2-phenyl-3-azoindole)indole/TCNE,3a and 1,2-diphenyl-3-(1,2-diphenyl-3-azoindole)indole/TCNQ,5b are reported. In the two complexes, the distances between donor and acceptor planes range between 3.4 and 3.5 A; in3a tetracyanoethylene faces the phenyl ring of the indole, while in5b the superposition of tetracyanoquinodimethane with the donor is negligible. Compound3a,P−1,a=9.504(2),b=9.513(3),c=8.941(2) A, α=97.81(4), β=103.38(3), γ=84.14(2)°,Z=2,Dcalc=2.55 g cm−3; compound5b,P−1,a=12.648(3),b=12.205(2),c=7.263(3) A, α=103.69(2), β=91.23(3), γ=110.61(2)°,Z=2,Dcalc=2.53 g cm−3.

There is an imperative need to distinguish stable from unstable and vulnerable plaques because of the occurrence of thrombosis following rupture of the plaque. Imaging techniques, invasive and noninvasive, are used routinely for the assessment of visualization and quantification of this pathology, even if invasive techniques cannot be applied in the screening of atherosclerotic plaques and noninvasive imaging has low reproducibility. The aim of this review was to verify the suitability and the advantages of using vibrational spectroscopy in the study of human atherosclerotic plaques. The utilization of validated vibrational techniques in clinical trials may be of great importance for the ability to diagnose the early onset of a disease, rapidly, noninvasively and unambiguously. These techniques, by using a worldwide accepted protocol in spectral investigation of bioclinical changes in the human body, have been successfully applied to assess vulnerable plaques in ex vivo and in vivo models, constituting a potentially useful support to classical clinical imaging techniques. It is conceivable that this fingerprinting approach, with further clinical validation, is ready to be developed for use and at the disposal of commercial and easy-to-use spectrometers, equipped with catheter-based systems for the in vivo imaging of atherosclerosis plaques.

Infrared spectra of phenanthrolines-perchloric acid hydrogen-bonded complexes are discussed together with x-ray results and theoretical calculations in order to verify the participation of ortho-hydrogens or ortho-methyls of phenanthroline in the complex formation. The role of through-bond and through-space contributions to hydrogen bonding is considered.

Spectroscopic, thermodynamic and kinetic properties of molecular interactions between indolizines and tetracyanoethylene are reported. The interactions involved in the complexes are weak as evidenced by the low formation constants. The kinetic behaviour indicates the initial formation of a pI-complex that is rapidly transformed into a σ-complex and thereafter into the final adduct(s). Apart from the results obtained by other techniques, infrared data clearly evidence vibrational contributes characteristic of the complexes, the tricyanovinyl derivatives and the tetracyanoethylene radical anion.

The formation of a charge-transfer complex between tetracyanoethylene (TCNE) and hexamethylbenzene (HMB) in isotactic polypropylene (PP) has been studied by using UV-VIS spectroscopy. The effective equilibrium constant of complex formation K e increases with the concentration of TCNE or HMB in the polymer. Hexadecane affects the K e in PP, while it has no influence on the complex in solution. The theory of non-uniform additives distribution in the polymer medium and the reactivity are discussed.

The kinetics of nitroxide formation on a polypropylene (PP) chain by reaction between carbonyl groups of γ-irradiated PP and 2-amino-2-methyl-1-propanol has been studied. During the reaction the total concentration of carbonyl and amine groups passes through a maximum. At the end of the reaction a weak ESR signal due to nitroxide groups was detected and its intensity was strongly enhanced by peroxidation with m-chloroperbenzoic acid. The presence of nitroxides after the reaction with the aminoalcohol has been explained by the interaction of an oxazolidine moiety with singlet oxygen coming from the decomposition of PP-hydroperoxides or by reaction of the latter compounds with the oxazolidine nucleus.

This study has been undertaken to investigate spectral features of cystic lesions of the jaw with the aim to understand their tumoral progression and to evidence initial signals of neoplastic changes. Three important groups (according to the World Health Organization classification) representing inflammatory (radicular) and developmental (orthokeratinized odontogenic, OOC) cysts as well as keratocystic odontogenic tumor (KCOT) of the jaw have been studied by microimaging infrared spectroscopy. From the spectral data analysed with the multivariate pattern recognition procedure, representative spectra were isolated and used to build correlation maps to localize the biochemical components in the tissue. The procedure enabled to better understand spectral features of these classes of cysts and to discriminate tumoral from non-tumoral spectra through the analysis of ‘vibrational markers’. In KCOT, the correlation of calcium derivatives (in metaplastic or displastic bones) with the tumor has been highlighted, too. The distribution of various biochemical components in the tissues, achieved through correlation maps of representative spectra, resulted in satisfactory agreement with the histopathological analysis. ‘Spectral isolation’ of micro tumorigenic zones in some normal OOC cysts, demonstrated the potentiality of infrared spectroscopy to evidence the early stage of a hidden lesion.

Stem cells are a promising source in a wide range of medical fields, included bone tissue regeneration. In this study, we investigated the molecular structure of dental pulp stem cells (DPSCs), during their differentiation towards the osteoblastic phenotype. DPSCs, easily achievable even from human young adults, were isolated from dental pulp of included third molar teeth and then cultured with appropriate medium to induce osteoblast differentiation. The FT-IR analysis of undifferentiated and differentiated DPSCs well pin-pointed biological changes during the osteogenic differentiation, above all in the Amide I, II and III vibrational modes as well as in the phosphate stretching vibrations. The spectroscopic study was supported by reverse transcriptase-polymerase chain reaction (RT-PCR) for the expression of specific osteoblastic markers, such as type I collagen (Coll-I), alkaline phosphatase (ALP), osteocalcin (OCN) and runt-related transcription factor 2 (RUNX2).

Indolizine dimers 1a–c are oxidized by chemical and electrochemical methods. Anodic oxidation shows that the title compounds are oxidized in two different steps, and cyclic voltammetry demonstrated their reversibility. The radical cations 2a–c and the dications 3a–c are characterized by an EPR study and by comproportionation reactions, respectively. The dimmers 1a–c, treated with diazonium ions, undergo retrogression reactions, forming the arylazoindolizines 7a and 7b. Formation of the radical cation 2b in the reaction of compound 1b with diazonium salts has been explained through the homolytic evolution of the intermediate σ-complex by means of an indolic aminoxyl as radical scavenger.

Indole, 2-methylindole, 2-phenylindole, and primary aromatic amines react with iodosobenzene dicetate leading both to 2-arylamino-3-arylimino-3H-indole in the case of indole and 2-methylindole, and to 2-phenyl-3-arylimino-3H-indole in the case of 2-phenylindole. The reaction is believed to proceed through the formation of a nitrenium ion formed by the interaction of iodosobenzene diacetate and primary aromatic amines and the mechanism is supported by experimental evidence

Spectroscopic, thermodynamic and kinetic properties of molecular interactions between indolizines and tetracyanoethylene are reported. The interactions involved in the complexes are weak as evidenced by the low formation constants. The kinetic behaviour indicates the initial formation of a pI-complex that is rapidly transformed into a σ-complex and thereafter into the final adduct(s). Apart from the results obtained by other techniques, infrared data clearly evidence vibrational contributes characteristic of the complexes, the tricyanovinyl derivatives and the tetracyanoethylene radical anion.

“Copyright © [2010] IEEE. Reprinted from ICTON 2010. ISBN: 978-1-4244-7799-9. This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs-permissions@ieee.org. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.” The characteristics of MZI-SOA are affected by its internal design yields and asymmetries, leading to an unbalanced power distribution at the output arms and difficult or non optimum biasing. Therefore, we propose an experimental methodology and model for MZI-SOA structures taking into account internal asymmetries as well as the internal SOA behaviour under different current both as what regards amplitude and phase.

Molecular associations of dihydrazones of 1,2-diketones with tetracyanoethylene are investigated and compared with those of the corresponding monohydrazones, in order to verify the influence of the second donor centre on the equilibrium constants. As proved by X-ray determinations (complex 2,3-butandionemonophenylhydrazone/tetracyanoethylene), hydrogen bonding appears to play an important role in the lattice stabilization of monohydrazones complexes. C10H12N2O·1/2C6N4,Mr=240.66, monoclinic,C2/c,a=12.216(2),b=12.824(3),c=16.784(2)A,β=93.74(2)°,Z=8,Dx=1.22 g cm−3,V=2623.8(8)A3, room temperature, CuKα, λ=1.5418 A,μ=6.28 cm−1,F(000)=1008,R=0.059 for 1398 independent observed reflections. The aromatic ring is planar and the tetracyanoethylene atoms are far more than 3.40 A from its barycentre. Together with van der Waals forces, H-bonding between two faced hydrazono molecules realizes the packing in the crystal.

2-Phenyl-3-phenylimino-3H-indole reacts with indole, 2-methylindole and 1,2-dimethylindole in the presence of stoichiometric trichloroacetic acid to form 1,2-dihydro-2-phenyl-2-(indol-3-yl-derivatives)-3-phenylimino-3H-indole, which during a longer period of time (16 hours) undergoes indolyl transposition to carbon-3 and elimination of aniline affording the 3,3′-bis-indolyls. In the case of 1,2-dimethylindole the intermediate coming from the indolyl migration may undergo a nucleophilic addition to carbon-2 of another molecule of indole; the new intermediate leads to the formation of 2-phenyl-3,3′-di-(1,2-dimethylindol-3-yl)-3H-indole by elimination of aniline and migration to carbon-3 of the second molecule of indole. By treatment with hydrochloric acid in refluxing ethanol, 1,2-dihydro-2-phenyl-2-(indol-3-yl-derivatives)-3-phenylimino-3H-indole afford to 3,3′-bis-indolyls and 1,2-dihydro-2-phenyl-2-(indol-3-yl-derivatives)-3H-indol-3-one (indoxyls). The crystal structure of 1,2-dihydro-2-phenyl-2-(indol-3-yl)-3-phenylimino-3H-indole is also reported. The latter compound does not give rearrangement products by acid treatment, only untreatable tarry material.

The reaction of substituted hydrazides with copper(II) chloride was investigated in the solid state or in solution in order to account for substituent effects. Spectroscopic results and values of the formation constants indicate the occurrence of strong complexes.

Molecular complexes of substituted indoles with π*-acceptors were investigated by means of Fourier transform infrared spectrometry under the conditions [D] 0 ⪢ [A] 0 , where [D] 0 and [A] 0 are the initial concentrations of the donor and acceptor, respectively. The formation constants of the complexes, evaluated on characteristic vibrational modes of the acceptors, are in substantial agreement with those determined by optical and nuclear magnetic resonance spectrometry.

Molecular complexes of mono and disubstituted [2.2]paracyclophanehydrazones with organic acceptors have been studied by means of thermodynamic and spectroscopic properties. Furthermore, the enhancement of the donor strength, induced by the hydrazono group, is viewed in the light of substituent as well as transannular effects.

N-nitrosodiphenylamine reacts with Grignard reagents forming symmetric dialkyl- or diarylhydroxylamines which are quantitatively converted into the corresponding nitroxyls by lead dioxide oxidation.

Methyl and methoxy substituted nitroarenes were reacted with acethophenone in the presence of sodium ethoxide in ethanol giving arylamino-conjugated diketo derivatives. A case ofipso-substitution of a methoxy group is discussed. The title compound C23H19NO2 (Mr=341.4) crystallizes in the monoclinic system, space groupP21/n witha=21.579(4),b=8.526(2),c=9.983(2) A;β=92.3(1)°;V=1835.2(7) A3,Z=4,Dc=1.24 g cm−3,μ(Cu-Kα)=5.9 cm−1, ϑ=1.5418 A,F(000)=720. The molecule adopts theE configuration with the C=O carbonyl groupstrans with respect to the ethylenic double bond.

Determinations of formation constants in complexes of anilines with tetracyanoethylene and fluoranil by Fourier transform IR spectrometry are reported. The kinetics of the disappearance complexes are in agreement with the literature. Results of attempts to follow the reaction in the solid state are reported.

On continuing our studies on head and neck neoplasia, specimens from salivary gland tumors have been explored by using infrared microimaging spectroscopy to discern healthy from neoplastic tissues. Samples with Warthin tumor, epithelial displasia, marginal B-cell lymphoma, low-grade adenocarcinoma, and adenoid cystic carcinoma pathologies have been investigated by using conventional light sources. Changes were monitored at the molecular level, probing spectral markers such as Amide I and II, phosphate, nucleic acids, and carbohydrates vibrational modes. In all cases, supervised and unsupervised spectral analyses resulted in satisfactory agreement with histopathological findings. Microsc. Res. Tech., 2009. © 2008 Wiley-Liss, Inc.

Benzofused heterocycles like 10H-[1]benzo thieno[3,2-b] indole and thieno[3,2-b]benzo[b]thiophene form molecular associations with π* organic acceptors. The weak interactions involved are viewed in terms of UV-Vis and IR techniques. The results, mainly in the case of complexes of 10H-[1]benzo thieno[3,2-b] indole, are in some disagreement with the literature. The structure of the complex 10H-[1]benzo thieno[3,2-b] indole/tetracyanoethylene is also reported. The four condensed rings constitute a conjugate system with significant lengthenings of the aromatic ring bonds and a shortening of those of the five-membered rings. The fragment as a whole is almost planar, and forms a dihedral angle of 39.9(1)° with the planar tetracyanoethylene molecule.

A series of complexes between 1-oxide quinolines and 7,7,8,8-tetracyanoquinodimethane has been synthesized and one of them has been analyzed by x-ray diffraction methods. Crystals of the title compound are monoclinic (C15H11NO·C12H4N4), space groupP21/n,a=44.525(4),b=7.326(2),c=6.531(2) A,β=90.23(3)°. The structure was solved by direct methods and refined by block-matrix least-squares to giveR=0.047 for 1865 reflections above 2σ(I). Molecular dimensions, interplanar distances, empirical method and IR spectra suggest a π-π* interaction with very low charge-transfer in the complex.