Hydrazones are versatile class of organic compounds with the general structure, R1R2C=NNHR3. Hydrazones of acetone, acetophenone, benzophenone, 2,2,2-trifluoroacetophenone and 2,2,2-triphenylacetophenone were synthesized and characterized by spectroscopic and computational methods using density functional theory (DFT) at B3LYP/6-31G*(d,p) basis set with SPARTAN 14 software. Results from spectroscopic analysis were compared with computational results. The compounds were all coloured with percentage yield 82.1, 82.6, 73.5, 69.4 and 88.4% respectively. UV-Vis spectra showed max in the UV region (355-385nm) and high molar absorptivity with the range going to the visible with high absorptivity. Mostly, high values of oscillator strength were recorded both in the experimental and calculated. Calculated vibrational frequencies assigned to C=N, N-N and N-H; 1706, 1147 and 3492; 1686, 1132 and 3467; 1665, 1128 and 3456; 1678, 1132 and 3489; 1664, 1115 and 3472cm-1 were in agreement with experimental IR vibrational frequencies: 1620.8, 1102.4 and 3456.0; 1618.4, 1129.0 and 3450.4; 1613.6, 1126.6 and 3462.4; 1618.4, 1109.0 and 3476.0; 1625.6, 1064.8 and 3440.0cm-1for all the hydrazones respectively. Variation of the substituent attached to the carbonyl carbon affected the values of the vibrational frequencies and bond lengths; this is as a result of distortion due to electronic and steric effects. The molecules exhibited high dipole moment from 6.69 to 8.38 Debye. High electrophilic index values were recorded from 5.5385 to 6.5504eV showing (2,2,2-trifluoroacetophenone with highest and 2,2,2-triphenylacetophenone with the lowest values, respectively). Polar surface area values range from 88.3 to 90.84 A2 and calculated log P values from-0.42 to 3.77.

The inhibiting activity of 3 sets of organic compounds ([2-[(2,3-dihydroxypropyl)sulfanyl]- N-octylacetamide (DSO), 2-[(2,3-dihydroxypropyl) sulfanyl]-N-decylacetamide (DSD) and 2-[(2,3-dihydroxypropyl) sulfanyl]-N-dodecylacetamide (DSDD)) were studied. The studied anti-corrosion compounds i.e. 2,3-dihydroxypropyl-sulfanyl derivatives were calculated using quantum chemical calculation and several descriptors (highest occupied molecular orbital energy (E-HOMO), lowest unoccupied molecular orbital energy (E-LUMO) and chemical reactivity indices (global electrophilicity index (omega), chemical hardness (eta), electronegativity (chi), local reactivity index, electron affinity and ionization potential) which described the anti-corrosion properties of the studied compounds were obtained. Fukui Indices for nucleophilic and electrophilic Attacks for inhibitors i.e. [2-[(2,3-dihydroxypropyl) sulfanyl]-N-octylacetamide (DSO), 2-[(2,3-dihydroxypropyl) sulfanyl]-N-decylacetamide (DSD) and 2-[(2,3-dihydroxypropyl) sulfanyl]-N-dodecylacetamide (DSDD) were observed and sites for nucleophilic and electrophilic attacks for DSO were C6 (0.047) and O3 (0.170); for DSD, the utmost value f(k)(+) was found on C6 (0.047), and the highest value f(k)(-) was located on C5 with 0.099 while the greatest value f(k)(+) was situated on C6 with 0.047 and the highest value f(k)(-) is found on C3 and C4 with 0.053 each for the DSDD molecule. The molecules used in this study was calculated using quantum chemical calculation and it was achieved using Spartan 14. More so, the QSAR study using multiple linear regression method was executed using Gretl 1.9.8. The selected descriptors among the entire calculated descriptors were used in the development of quantitative structural activity relationship (QSAR) model and the developed model replicated the observed %IE. The correlation coefficient (R-2) was calculated to be 0.926, cross validation (CV.R-2) was 0.963 and adjusted R-2 was 0.852. Also, E-LUMO was the predominating parameter in the corrosion inhibition property of the studied compounds.

Theoretical studies were carried out to investigate the thermal decomposition of ethyl dithiocarbonates (xanthate) using Hartree–Fock at the HF/321-G* level and the density functional method with Becke 3 Lee Yang pair DFT/(B3LYP), 6-31G*, 6-31G**, 6-31+G*, MP2 and CCSD in the ab initio method of calculation using Spartan 10. Geometric parameters, such as the bond length, bond angles, dihedral angles, heat of formation, atomic charges and vibrational frequencies, were obtained. The data were used to calculate the thermodynamics parameters, change in entropy ΔS, enthalpy change ΔH, free energy G, pre-exponential factor A, rate k at 623 K, and variation of rate k with temperatures from 498–623 K at temperature intervals of 25 K. It was observed that the values obtained are in good agreement with the experimental values for the ab initio methods, and according to Arrhenius theory, the calculated rate k increases with increasing temperature.

Polymers that efficiently interrelate with biological systems have fascinated a lot of curiosity in biosensor application. In order to determine their suitability and conducting abilities, the nature of ground state, excited states properties and binding affinities of such systems must be known. The vertical singlet-triplet gap, electronic transitions of 3-methyl-pyrrole-1-carboxylic acid has been studied using Spin-Flip Time density Functional Theory (SF-TDDFT) method with 6-311++G(d,p) basis set. All calculations were carried out using quantum mechanical softwares. Results revealed the Highest Occupied Molecular Orbital (HOMO) energies vary within the range of -5.22 to -6.24, while Lowest Occupied Molecular Orbital (LUMO) energies vary (from -0.62 to -1.84). Result revealed that the singlet-singlet transition for 3, 4 and 5 rings of MPC basically involves four (|H >, |H-1 >, |L > and |L+1 >) transitions. Result show a non-zero transition dipole moment (dnm) for MPC monomer and tetramer (Allowed transition), while dnm decreases for trimer, dimer and pentmer, due to the triple integral returning an ungerade (odd) product and redistribute electrons within the same orbital and will return a zero product.

Background: Conjugated systems are of great interest to chemists, particularly photochemists and spectroscopists.Benzophenone (BP), a highly conjugated compound is a well-known compound attracting keen interest from photochemist.Methodology: A comparative knowledge of the nature of ground state of dimethoxythiobenzophenone (DMTB) and dimethoxybenzophenone, their geometries, band gaps, absorption and transition properties will be a valuable contribution for further studies and practical applications.Results: The UV analysis of benzophenone (BP) in two solvents (ethanol, ε = 24.5 and n-hexane, ε = 1.88) and FT-IR correlated with Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TDDFT) of benzophenone (BP), thiobenzophenone (TBP), dimethoxybenzophenone (DMB) and dimethoxythiobenzophenone (DMTB) suggests a singlet ground state.Conclusion: The DMTB absorbs at the visible region with a lower band gap than DMB.The BP exhibits two bands: (I) A red shift from 247.6 nm (non-polar solvent) to 252.3 (polar solvent), )λ = +4.7 nm and (II) A blue shift from 205.3 nm (non-polar solvent) to 197.7 nm (polar solvent), )λ = -7.6 nm.This shows that band I is likely to be π6π* and band II n6π*.The DMB like BP absorbs at the UV region of the spectrum and unlike DMTB whose absorption is principally at the visible region.The DMTB showed a longer bond length of the thiocarbonyl (C=S) than carbonyl (C=O) in BP and DMB.

A detailed geochemical study of oil samples from an onshore field in the Niger Delta was carried out for their characterization and correlation. The samples were analyzed using Gas Chromatographic (GC), Gas Chromatographic-Mass Spectrometric (GC-MS) and Inductively Coupled Plasma-Mass Spectrometric (ICP-MS) analytical techniques. The results showed that CPI, Pr/Ph, Pr/nC17, Ph/nC18 and odd/even ratios ranged from 0.91 to 1.17, 3.07 to 6.04, 0.39 to 0.80, 0.14 to 3.30 and 1.33 to 1.39 respectively. The concentration levels of Co, Cr, Cu, Fe, Ni and V ranged from 0.9 to 32, 6.2 to 24, 3.31 to 19.4, 11.4 to 1241, 26.3 to 144 and 11.0 to 29.7 pbb respectively. The Pr/nC17 vs. Ph/nC18 plot revealed two oil types; non-degraded and minor degraded oils, which were derived from organic matter deposited in transitional environments. This suggests that both oil types have identical source rocks. Also, CPI values of 0.91 to 1.17 indicated that the oils are thermally mature. Biomarker data also discriminated the oils into two groups on the basis of biodegradation and revealed that the oils are mature and generated at almost the same thermal maturity level. The results of Ni vs. V, Co/Ni vs. V/Ni cross plots and cluster analysis similarly revealed identical two oil types. The similarity in the results of both organic and inorganic geochemistry of these oils shows that an integrated organic and inorganic geochemical data provide a reliable tool for the evaluation, characterization and correlation of crude oils.

A suite of oil samples from an onshore–swamp field in the northwestern Niger Delta was analyzed using whole oil gas chromatography. The oil samples were analyzed to correlate the oils and to evaluate post generative alterations using light hydrocarbons. Light hydrocarbon based parameters were compared with higher molecular weight hydrocarbon correlation based parameters. Two distinct oil groups were identified based on light hydrocarbon parameters, which agreed with the correlation based on higher molecular weight hydrocarbon parameters. The discrimination of the two groups is a reflection of post generative alteration–biodegradation. The study showed that light hydrocarbon distribution has strong influence on evaporative fractionation of the oils. It also revealed that the process that initiates biodegradation has significant influence on carbocyclic ring closure.

Thirty four shale samples from the Tertiary Agbada Formation were analysed for TOC and Rock‐Eval pyrolysis parameters in order to evaluate the effect of oil‐based mud contamination on source‐rock characterization. The samples were obtained from five wells in the offshore Niger Delta over a depth range of 5,460ft to 11,580ft. The results indicated that the raw (unextracted) samples were dominated by Type III kerogen. However, after extraction, both Types II/III and III kerogen were identified, consistent with previous studies. These results demonstrate that it is essential that shale samples should be extracted prior to TOC and Rock‐Eval pyrolysis for accurate source‐rock evaluation.

13C NMR spectra of thiophenol, 4-nitrothiophenol, 4-X-thioanisole (X = NO2, NH2, SH, H) were examined in CDCl3 solution. Substituent chemical shift values (additivity parameters) for the −SH and −SCH3 groups are reported.

Nine different species of mushroom were analysed spectrometrically for their vanadium contents. It was found that some edible species of mushroom, such as Agrocybe and Leutinus, contain vanadium in amounts either comparable with, or higher than, the amounts in some poisonous species. The result suggests that there is no correlation between the vanadium content of the mushroom species examined and their toxicity.

Radical intermediates obtained in the photoreduction of 2,6-dimethyl-γ-pyrone, γ-pyrone-2,6-dicarboxylic acid and its anion have been identified by the ESR technique. Persistent secondary radicals were observed in the chelidonic acid system. While carbon centred radicals add to the ethylenic bond of the heterocyclic compounds, organometallic radicals preferentially add to the oxygen of the carbonyl group.

The addition of PO2−3, CO−2 and SO−4 radicals to the trans—trans muconate anion was studied by electron spin resonance spectroscopy. While CO−2 and SO−4 add exclusively to the terminal carbons of the muconate anion, PO2−3 adds to both C1 and C2 carbon atoms. The preferential addition of free radicals to the terminal carbons is consistent with the higher free valence index of the terminal carbons.

2-Isopropoxy-1,4-naphthoquinone has been used as a photoredox reagent in non-silver imaging process. The present study showed that the photoreactions of this quinone are very sensitive to solvent due to the competing intramolecular hydrogen abstraction from the isopropoxy group. The presence of cobalt acetylacetonate often modifies the reactions which leads to a very high quantum efficiency of producing the radical intermediates. The ether oxygen in the 2-substituent provides a further coordinating site for organometallic compounds and the quinone behaves as a 1,2-quinone when interacting with metals.

The esr and CIDEP results show that the photoreduction of chromones and chromanones by phenol and by triethylamine proceeds via a spin polarized T(n,π*) triplet state which abstracts a hydrogen atom from the donor. Both chromone and chromanone are found to be reactive to the addition of organometallic radicals to form some radical adducts, including organotin, organosilicon, and organogermane.

The ESR spectra of seventeen oxovanadium(IV) β-diketonates in chloroform solution have been examined in order to study the effect of various substituents. Bis[4,4,4-trifluoro-1-(3-pyridyl)-1,3-butanedionato]oxovadium(IV) which is tetrameric in chloroform solution gave an ESR spectrum suggestive of a species with a long rotation correlation time. Both 3-chloro and 3-methyl substituents increase the in-plane ligand field in VO(3-Clacac)2 and VO(3-CH3acac)2 while p-methoxyphenyl substituent which has the highest possible mesomeric interaction among the substituents gave the lowest isotropic splitting factor.

Various reactions of Group IVB organometallic radicals with 4,4′-dimethoxybenzophenone, 4,4′-dimethoxythiobenzophenone, and 3-ethyl-2-thioxo-4-oxazolidione were studied by ESR spectroscopy. The greater involvement of sulfur in comparison with oxygen in spin delocalization is clearly reflected in both the hyperfine coupling constants and the g-factors. In general, thiocarbonyl compounds appear to be more efficient in forming radical adducts than the corresponding carbonyl compounds but the overall reactions depend strongly upon the structure of the thiocarbonyl compounds.

The photooxidation of vitamin C by pyruvic acid and its derivatives, duroquinone, and vitamin K1, is systematically studied by the combined esr and time-resolved CIDEP technique. Because of the unique property of the triplet pyruvic acid which is different from that of the duroquinone triplet, the choice of these model systems allowed the CIDEP observations of the initial polarization of the ascorbate radical anion and its counter primary radical in either the enhanced absorptive or the emissive mode. The results demonstrate the efficient photooxidation of vitamin C by the triplet vitamin K1 and that the latter triplet possesses similar properties as the triplet quinones. In the photooxidation system involving vitamin C and pyruvic acid, the adjustment of the pH of the aqueous solution afforded an opportunity to observe the photochemical reaction between two anions, the pyruvate anion and the ascorbate anion. Arguments were made in favor of an electron transfer mechanism for the oxidation of vitamin C by triplet vitamin K1 but against the electron transfer mechanism for the oxidation of vitamin C by triplet pyruvate anion. T1 values of the primary radicals estimated from their CIDEP transient responses at low microwave power are reported and it was suggested that the hydrogen-bonding capacity of the ascorbate radical anion in water does not contribute significantly to the relative difference of T1's between itself and the counter pyruvic ketyl radical.

ESR‐spektroskopische Untersuchungen zeigen, daß sich Phenylsilyl‐Radikale an die p‐Chinone (III) unter Bildung der p‐Silyloxy‐substituierten Phenoxyl‐Radikale (I) addieren.