Straight-chain Carboxylic Acids Research Articles

Impact of HZSM-5 supported Fe, Ni, and Mo catalysts on microcrystalline cellulose liquefied bio-oil composition

The effects of Fe, Ni, and Mo active components loaded with HZSM-5 on the composition of hydrothermal liquefaction bio-oil from microcrystalline cellulose were investigated. All three supported catalysts resulted in the cyclization of microcrystalline cellulose into aromatic compounds. Additionally, Fe/HZSM-5 underwent oxidation, producing ketones, aldehydes and carboxylic acids, which accounted for 44.5% of the total composition of bio-oil. On the other hand, Ni/HZSM-5 and Mo/ZHSM-5 caused ring-opening of microcrystalline cellulose, leading to the production of alcohols and hydrocarbons, constituting 23.05% and 36.46% of the total composition, respectively. These findings indicate that the catalysts not only facilitated the ring-opening of polycyclic rings in microcrystalline cellulose but also underwent reactions with the hydroxyl groups present. To further understand the impact of these catalysts on hydroxyl groups similar to microcrystalline cellulose, glycerol was used as a model compound for liquefaction. The results revealed that 40.72% of Fe/HZSM-5 bio-oils consisted of cyclic ketones, while Ni/HZSM-5 predominantly produced straight-chain alkanes, straight-chain lipids, and straight-chain carboxylic acids. In contrast, Mo/HZSM-5 primarily yielded six-membered cyclic carboxylic acids, accounting for 72.48% of the composition.

Electrochemical Plasma for Treating 2,4,5-Trichlorophenoxyacetic Acid in a Water Environment Using Iron Electrodes.

Herbicide compounds containing aromatic rings and chlorine atoms, such as 2,4,5-trichlorophenoxyacetic (2,4,5-T), cause serious environmental pollution. Furthermore, these compounds are very difficult to decompose by chemical, physical, and biological techniques. Fortunately, the high-voltage direct current electrochemical technique can be controlled to form a plasma on metallic electrodes. It creates active species, such as H2, O2, and H2O2, and free radicals, such as H•, O•, and OH•. Free radicals that have a high oxidation potential (e.g., OH•) are highly effective in oxidizing benzene-oring compounds. Iron electrodes are used in the study to combine the dissolving process of the iron anode electrode to create Fe2+ ions and the electrochemical Fenton reaction. In addition, the flocculation process by Fe(OH)2 also occurs and the plasma appears with a voltage of 5 kV on the iron electrode in a solution of 30 mg L–1 of 2,4,5-T. After a period of time of the reaction, the aromatic-oring compounds containing chlorine were effectively treated, and the electric conductivity of the solution increased due to the amount of Cl– ions released in the solution and the decrease in the pH value. The degradable products of 2,4,5-T were qualitatively characterized by gas chromatography–mass spectrometry (GC–MS), and it was determined that straight-chain carboxylic acids are formed in the solution. These compounds are easy to oxidize thoroughly under appropriate conditions in a solution via OH• free radicals. Moreover, 2,4,5-T was also quantitatively analyzed using a calibration curve from GC–MS and high-performance liquid chromatography (HPLC). Furthermore, this work also suggests that the performance of the treatment process can be optimized by controlling the technological factors, such as the input voltage, the distance between anodic and cathodic electrodes, the initial concentration of 2,4,5-T, and flowing air through the solution that represents an approximately 99.83% degradable efficiency. Finally, the work demonstrates a potential technology for treating the 2,4,5-T compound, particularly for environmental pollution treatments.

Carboxylic acid responses by a conserved odorant receptor in culicine vector mosquitoes

Many mosquito behaviours that are critical for survival and reproduction depend upon timely responses to chemical cues. Of interest are the effects of volatile organic compounds like carboxylic acids (CAs) that are released by potential blood meal hosts. Short chain CAs are among the primary attractants for host-seeking females and influence host selection in vector species. Although the behavioural relevance of CA's has been established, less is known about the molecular receptive events that evoke responses to specific compounds, with the Ir family of chemoreceptors being broadly implicated in their detection. In this study, we demonstrate that Or orthologs from two vector species, Aedes aegypti (L.) and Aedes albopictus (Skuse), are selectively activated by straight chain carboxylic acids and that these responses are attenuated by the commercial insect repellant N,N-Diethyl-meta-toluamide. Our results suggest that multiple chemoreceptors, representing diverse families, are able to mediate molecular responses to CAs and may therefore underlie important behaviours that directly impact disease-transmission cycles.

Blending studies with selected waterbuck odor constituents or analogues in the development of a potent repellent blend against savannah tsetse

Previous comparison of the body odors of tsetse-refractory waterbuck and those of tsetse-attractive ox and buffalo showed that a blend of 15 EAG-active compounds specific to waterbuck, including C5–C10 straight chain carboxylic acid homologues, methyl ketones (C8–C12 straight chain homologues and geranyl acetone), phenols (guaiacol and carvacrol) and δ-octalactone, was repellent to tsetse. A blend of four components selected from each class of compounds (δ-octalactone, pentanoic acid, guaiacol, and geranylacetone) showed repellence that is comparable to that of the 15 components blend and can provide substantial protection to cattle (more than 80%) from tsetse bites and trypanosome infections. Structure-activity studies with the lactone and phenol analogues showed that δ-nonalactone and 4-methylguaiacol are significantly more repellent than δ-octalactone and guaiacol, respectively. In the present study, we compared the responses of Glossina pallidipes and Glossina morsitans to i) blends comprising of various combinations of the most active analogues from each class of compounds, and ii) a four-component blend of δ-nonalactone, heptanoic acid, 4-methylguaiacol and geranyl acetone in different ratios in a two-choice wind-tunnel, followed by a field study with G. pallidipes population in a completely randomized Latin Square Design set ups. In the wind tunnel experiments, the blend of the four compounds in 6:4:2:1 ratio was found to be significantly more repellent (94.53%) than that in 1:1:1:1 proportion and those in other ratios. G. m. morsitans also showed a similar pattern of results. In field experiments with G. pallidipes population, the 6:4:2:1 blend of the four compounds also gave similar results. The results lay down useful groundwork in the large-scale development of more effective ‘push’ and ‘push-pull’ control tactics of the tsetse flies.

Application of Acetyl-CoA synthetase from Methanothermobacter thermautotrophicus to non-native substrates

The substrate selectivity of the Trp416Gly mutant of Methanothermobacter thermautotrophicus acetyl-CoA synthetase (Trp416Gly MT-ACS1) was explored. The goal was to identify its substrate range, particularly for functionalized carboxylic acid substrates that would allow post-synthesis functionalization of CoA thioesters or downstream products using metathesis or Click chemistry. Relative activities were determined by in situ formation of acyl-hydroxamate iron (III) complexes. Trp416Gly MT-ACS1 showed good activities for saturated straight chain carboxylic acids from C2 to C8, for ω-alkenyl straight chain carboxylic acids from C4 to C7 and for ω-alkynyl straight chain carboxylic acids from C5 to C7. Carboxylic acids showing ≥20% conversion in screening reactions were used in preparative conversions that completely consumed the added CoASH.

Soil water repellency: A molecular-level perspective of a global environmental phenomenon

Soil water repellency affects vast regions of agricultural and native land across the globe. Sandy soils are most likely to develop non-wetting characteristics with susceptibility decreasing with clay content. This study uses molecular dynamics simulations combined with laboratory scale experiments to study the interactions and assembly of saturated C16 straight chain alcohol and carboxylic acid molecules on a range of soil surfaces. The development of severe water repellency on sand at low loading levels of palmitic acid (0.75 × 10−6 mol g−1) is explained in terms of favourable H-bonding with silica surfaces and the development of 2–3 layers of lateral aligned organic molecules on the mineral surface. The efficacy of kaolinite in lowering soil water repellency is attributed to the higher surface area of this mineral and favourable surface chemistry, which hinders formation of persistent organic multilayers.

The effect of organic acids and salinity on the interfacial tension of n-decane/ water systems

We have investigated how a homologous series of straight-chain carboxylic acids with a cyclohexyl substituent in the opposite end of the functional groups impacts the interfacial tension (IFT) between decane (oil) and water. The employed method was the pendant droplet technique. We do not observe any striking effect of expanding the chain length: all acids reduced the IFT compared to water by approximately 20 mN/m. Additionally, the effect of changing the chemical character and the concentration of the cation in a series of brines where studied too, and again we do not observe a significant IFT impact. The only modification that significantly reduces the IFT is the modification of the anion from chloride to carbonate, a change that results in an increased pH and thus a transformation of the constituent acids from their neutral to their anionic form. This is expected to result in a reduced IFT because of the polar end of the surfactant is even more polar which alleviates the stress on the surface.

A Comprehensive Study on Metal Triflate-Promoted Hydrogenolysis of Lactones to Carboxylic Acids: From Synthetic and Mechanistic Perspectives

Direct hydrogenolysis of lactone to carboxylic acid (i.e., hydrogenolysis of the Calkoxy–O bond with the carbonyl group untouched) is generally difficult, as the current strategies employing Bronsted acids as the catalyst usually require harsh conditions such as a high temperature and a high H2 pressure. Herein, we report a developed solvent-free catalytic transformation, in which W(OTf)6 is believed to promote the hydrogenolysis process. This strategy could efficiently hydrogenate lactones to carboxylic acids under extra mild conditions (e.g., a reaction temperature of <150 °C and 1 atm of H2) and showed a broad substrate scope. In addition, the catalytic protocol can be further applied to the hydrogenolysis of polyhydroxyalkanoate, as a renewable polymer, to the corresponding straight-chain carboxylic acids. An extensive mechanistic study was subsequently performed, and the density functional theory calculations revealed a reaction pattern, including the complete cleavage of the C═O bond with the assist...

Repellency of tsetse-refractory waterbuck (Kobus defassa) body odour to Glossina pallidipes (Diptera: Glossinidae): Assessment of relative contribution of different classes and individual constituents

Our earlier studies on the comparative behavioural responses of caged savanna tsetse (Glossina morsitans morsitans and Glossina pallidipes) on a preferred host (ox) and a non-host (waterbuck) suggested the presence of allomonal constituents on the latter. Follow up comparison of the compositions of odours of waterbuck with those of ox and buffalo led to the identification of a series of compounds (15) specific to waterbuck, including straight chain carboxylic acid (C5–C10), phenols (guaiacol and carvacrol), 2-alkanone homologues (C8–C12), geranylacetone and δ-octalactone. Behavioural studies in a windtunnel in the laboratory suggested that G. m. morsitans was repelled by a synthetic blend of waterbuck-specific constituents. In the present study, the effects of different blends of these compounds on catches of mixed sexes of G. pallidipes in attractant-baited NG2G traps were evaluated in the field. Each multicomponent class of constituents (acids, ketones and phenols) was found to reduce fly catches, but a 14-component blend of all these compounds was more effective (reduced catches by 79–85%), indicating that each of these classes of compounds contributes incrementally to the repellency of the waterbuck odour. However, subtractive assays showed some redundancy within each class of compounds, with some even demonstrating attractive properties. Addition of (RS)-δ-octalactone to the 14-component significantly increased the repellency of the resulting blend. A 5-component blend of compounds selected on the basis of their relative performance in subtractive assays (δ-octalactone, guaiacol, geranylacetone, hexanoic and pentanoic acid) showed substantial reduction in fly catches (84%) relative to the baited control. In separate sets of experiments involving an ox tethered in the middle of an incomplete ring of electric screens in the presence or absence of 15-component or 5-component blends, comparable levels in the reduction of fed flies (94 and 96%, respectively) were obtained with the two blends. The chemo-ecological significance and practical implication of these results are highlighted.

Relative molar responses of some compounds containing oxygen and nitrogen in GC–MS

Relative molar responses (RMRs) of some straight-chain aliphatic alkanes, ketones, aldehydes, alcohols, carboxylic acids, primary amines, aniline, and nitrobenzene derivatives were investigated related to naphthalene. Most of the respective compounds have not been investigated yet due to their high polarity or high boiling point. The earlier cross section data for oxygenated compounds were changed to RMRs which are more utilizable from an analytical aspect. A linear correlation was found between the RMRs and the carbon atom numbers in primary amines. In the cases of aniline and nitrobenzene derivatives the RMRs were also determined; however, no functional relationship was found. The measurement conditions, i.e., the type of column affect the apparent RMRs of aliphatic primary amines. A midpolar column having a higher maximum operating temperature provides a more sensitive apparent RMR (Rtx-1701) than the basic polar column having a lower maximum temperature (Stabilwax-DB), because a high temperature allows setting a higher injector temperature and a higher amount of compound can reach the ion source. Knowing correlations the quantitative analysis passes into easier and fewer reference materials are needed to investigate a sample having many components, because the sensitivities can be determined from the correlations studied in this paper. This is also valid for aromatic compounds, even though no functional relationship exists.

Steric effects of carboxylic capping ligands on the growth of the CdSe quantum dots

Cadmium selenide quantum dots were grown using different carboxylic capping ligands in order to study the steric effects of the ligand chain length and chain branching. Straight chain and branched saturated carboxylic acids (fatty acids) were used as capping ligands. Hot injection synthesis was performed in 1-octadecene via the reaction between Cd carboxylates and trioctylphosphine selenide. At specific times, samples were withdrawn from reaction mixtures. For straight chain carboxylic acids, namely stearic, hexadecanoic, dodecanoic, decanoic, and octanoic, the decrease of the chain length leads to the increase of the CdSe particle sizes due to the faster transport of the monomers through the capping layer. For decanoic and octanoic acids, fast diffusion through the capping layer leads to the reaction-controlled kinetics, and the particles grow as tetrapods instead of dots. α-Branched double chain acids, 2-butyloctanoic and especially 2-hexyldecanoic, create more steric hindrance compared to the straight chain acids of comparable length and produce smaller quantum dots. α-Branched triple chain acids, neodecanoic and 1-adamantanecarboxylic, were expected to show superior steric hindrance during the synthesis. Neodecanoic acid, compared to 2-butyloctanoic acid, the closest to it in length, created less hindrance for the monomer diffusion, probably because two of its three branches are very short. 1-Adamantanecarboxylic acid performed comparable to 2-butyloctanoic acid, despite a much shorter length. This is attributed to the bulky rigid adamantane cages forming a dense capping layer. Straight chain and branched chain ligands lead to different photoluminescence patterns. When capped with straight chain carboxylates, CdSe quantum dots exhibit only sharp bandgap fluorescence, consistent with a high degree of surface site coverage. All of the α-branched ligands enabled intense surface trap emission, likely because of incomplete passivation of the surface atoms due to the nearest neighbor steric repulsion.

Extraction of copper(II) with 1,2-diacylhydrazines in the presence of associated metals

Conditions of Cu(II), Zn(II), Ni(II), Co(II), and Fe(III) ions extraction (pH values, effect of reagent amount) with symmetrical 1,2-diacylhydrazines derived from straight-chain aliphatic carboxylic acids and α-branched higher carboxylic acids Versatic-10 were studied. The separation coefficients of element pairs and pH of half extraction were calculated. The values of [Cu(II)]: [reagent] ratios in extracted complexes were determined. 1,2-Diacylhydrazines were shown to be more selective extractants toward nonferrous metal ions as compared with carboxylic acids, while the branching and elongation of alkyl chain in the reagents enhances their extraction properties and compatibility with hydrocarbon solvents.

Nano-Sized, Hydrolytically Stable Ternary Oxovanadium(IV) Complexes With Bidentate Ligands

A novel route to synthesize ternary oxovanadium(IV) complexes containing straight chain carboxylic acids and Schiff bases has been investigated. Complexes with the general formula [VO(OOCR)(SB)] (R˭C13H27, C15H31, or C17H35 and HSB = Schiff bases) have been isolated and characterized. The complexes were characterized by elemental analyses, molecular weight determinations, cyclic voltammetry, and spectral studies. Powder XRD and TEM studies indicated the particles of these were lying in the nano-size range. These are novel hydrolytically stable, mixed-ligand complexes in which vanadium is having coordination number 5. A square pyramidal geometry around vanadium has been assigned in all the complexes.

Spectroscopic studies of oxo-centered, carboxylate-bridged, trinuclear mixed-valence iron (ІІІ, ІІІ, ІІ) complexes with aromatic hydroxycarboxylic acids

New type of oxo-centered, carboxylate-bridged, trinuclear, mixed-valence iron complexes of the general formula [Fe3O(OOCR)3(OOCR*)3L3] (where R=C13H27 or C15H31 and R*=C6H4(OH), (R′); C6H5CH(OH), (R″) or (C6H5)2C(OH), (R‴) and L=Methanol) were synthesized by the reaction of [Fe3O(OOCCH3)6(H2O)3] with straight chain carboxylic acids and aromatic hydroxycarboxylic acids. These were characterized by elemental analyses, spectral (electronic, infrared, Mössbauer, FAB mass and powder XRD) studies, conductance and magnetic susceptibility measurements. Infrared spectra suggested bidentate and bridging mode of coordination of both the carboxylate and hydroxycarboxylate anions along with Fe3O vibrations in the complexes. Mössbauer parameters indicated the presence of high-spin Fe(ІІ) (S=2) and high-spin Fe(ІІІ) (S=5/2) centers in the complexes, confirming the valence-localized type of species. An intervalence-transfer band observed at 13,690–13,850cm−1 range in the room-temperature electronic spectra of the complexes also suggested the complexes containing iron in mixed-valence state. Trinuclear nature of the complexes was confirmed by their FAB mass spectra. Magnetic moment values displayed octahedral geometry around each iron in the complexes and a net anti-ferromagnetic exchange coupling via μ-oxo atom related to mixed-valence pairs. A plausible structure for these complexes has been established on the basis of spectra and magnetic moment data.

The Potential for Using Ozone to Decrease Pesticide Residues in Honey Bee Comb

Ozone is a strong oxidizer, and we evaluated its potential to eliminate pesticides from honeycomb and empty honey bee hives. Honey bees are exposed to pesticides when foraging for nectar and pollen and when beekeepers use in-hive chemical pest control measures. Persistent pesticides can accumulate in the hive over years, potentially harming the bees. Honeycomb is removed from bee colonies for honey extraction and then placed back on the colonies at a later date, providing a time when combs could be fumigated to eliminate or reduce pesticide residues. We found that ozone gas at a rate >920 mg O3/m3 for 10-20 h lowers coumaphos residues on a glass surface by 93-100% and tau-fluvalinate by 75-98%. Ozone was less effective at eliminating pesticides on beeswax, and residues were more effectively eliminated with new combs (comb built by bees within 3 y) than with old combs (combs used by beekeepers for >10 y). Ozone significantly reduced dimethylphenyl formamide, chlorpyrifos, and fenpyroximate contaminations in comb. When comb is treated with ozone, an off-odor is created, but the volatiles were found to be primarily straight chain aldehydes and carboxylic acids that are probably harmless to bees and humans. Ozone may have some utility for lowering pesticide residues in bee hives, but it would be more effective if a mechanism could be found that provides better penetration into wax, a goal not fully accomplished in our method.

Aromatic units from the macromolecular material in meteorites: Molecular probes of cosmic environments

Ancient meteorites contain several percent of organic matter that represents a chronicle of chemical evolution in the early solar system. Aromatic hydrocarbon units make up the majority of meteorite organic matter but reading their record of organic evolution is not straightforward and their formation mechanisms have remained elusive. Most aromatic units reside in a macromolecular material and new perceptions of its structure have been provided by a novel on-line hydrogenation approach. When applied to the Orgueil (CI1) and Murchison (CM2) meteorites the technique releases a range of aromatic hydrocarbons along with some oxygen, sulphur and nitrogen-containing aromatic units. When on-line hydrogenation is compared to conventional pyrolysis, more high molecular weight units and a wider range of liberated entities are evident. Comparisons of results from Orgueil and Murchison reveal variations that are most likely related to differing levels of parent body alteration. The enhancement of straight-chain hydrocarbons (n-alkanes) in the hydrogenation products imply a source of these common contaminants from straight-chain carboxylic acid (n-alkanoic acid) precursors, perhaps from bacterial contributions on Earth. The on-line hydrogenation data also highlight a long-standing but unexplained observation related to the relative preference for specific isomers in methyl-substituted benzenes (meta-, ortho- and para-xylenes). The new hydrogenation approach appears to release and transform macromolecular material meta-structures (benzenes with substituents separated by single carbon atoms) into their free hydrocarbon counterparts. Their release characteristics suggest that the meta-structures are bound by oxygen-linkages. The meta-structures may be molecular probes of specific ancient cosmic environments. Parent body processing may have performed a similar function as hydrogenation to produce the most common meta configuration for free substituted benzenes. Notably, this isomeric preference for substituted benzenes is relatively distinctive for meteorites and can help in the discrimination of meteorite-derived and fossil biology-derived organic matter on Earth and on Mars.

Understanding biocatalyst inhibition by carboxylic acids

Carboxylic acids are an attractive biorenewable chemical in terms of their flexibility and usage as precursors for a variety of industrial chemicals. It has been demonstrated that such carboxylic acids can be fermentatively produced using engineered microbes, such as Escherichia coli and Saccharomyces cerevisiae. However, like many other attractive biorenewable fuels and chemicals, carboxylic acids become inhibitory to these microbes at concentrations below the desired yield and titer. In fact, their potency as microbial inhibitors is highlighted by the fact that many of these carboxylic acids are routinely used as food preservatives. This review highlights the current knowledge regarding the impact that saturated, straight-chain carboxylic acids, such as hexanoic, octanoic, decanoic, and lauric acids can have on E. coli and S. cerevisiae, with the goal of identifying metabolic engineering strategies to increase robustness. Key effects of these carboxylic acids include damage to the cell membrane and a decrease of the microbial internal pH. Certain changes in cell membrane properties, such as composition, fluidity, integrity, and hydrophobicity, and intracellular pH are often associated with increased tolerance. The availability of appropriate exporters, such as Pdr12, can also increase tolerance. The effect on metabolic processes, such as maintaining appropriate respiratory function, regulation of Lrp activity and inhibition of production of key metabolites such as methionine, are also considered. Understanding the mechanisms of biocatalyst inhibition by these desirable products can aid in the engineering of robust strains with improved industrial performance.

Spectroscopic investigations of nano-sized titanium(IV) complexes containing electron-rich oxygen-based ligands

A convenient method has been explored to synthesize some nano-sized, mixed-ligand complexes of titanium(IV) with the general formula [Ti(acac)Cl2−n(L)n(OOCC15H31)] (where Hacac=acetylacetone, HL=dibenzoylmethane or benzoylacetone and n=1 or 2). They have been synthesized by stepwise substitutions of chloride ions from titanium(IV) chloride with straight chain carboxylic acid and β-diketones. These were characterized by elemental analyses, molecular weight determinations, spectral (electronic, FTIR, 1H NMR and powder XRD) and TEM studies. Conductance measurements indicated their non-conducting nature which may behave like insulators. Bidentate chelating nature of carboxylate and β-diketones anions in the complexes was established by their infrared spectra. LMCT bands were observed in the electronic spectra. Molecular weight determinations indicated mononuclear nature of the complexes. Powder XRD and transmission electron microscopy (TEM) studies indicated the particles of these were lying in the nano-size range. The complexes exhibited high resistance to hydrolysis. On the basis of these studies, coordination number 7 or 8 is assigned for titanium in the synthesized complexes.

Synthesis and spectral characterization of trinuclear, oxo-centered, carboxylate-bridged, mixed-valence iron complexes with Schiff bases

Some novel trinuclear, oxo-centered, carboxylate-bridged, mixed-valence iron complexes of the general formula [Fe3O(OOCR)3(SB)3L3] (where R=C13H27, C15H31 or C17H35, HSB=Schiff bases and L=Ethanol) have been synthesized by the stepwise substitutions of acetate ions from μ3-oxo-hexa(acetato)tri(aqua)iron(II)diiron(III), first with straight chain carboxylic acids and then with Schiff bases. The complexes were characterized by elemental analyses, molecular weight determinations and spectral (electronic, infrared, FAB mass, Mössbauer and powder XRD) studies. Molar conductance measurements indicated the complexes to be non-electrolytes in nitrobenzene. Bridging nature of carboxylate and Schiff base anions in the complexes was established by their infrared spectra. Mössbauer spectroscopic studies indicated two quadrupole-split doublets due to Fe(II) and Fe(III) ions at 80, 200 and 295K, confirming the complexes are mixed-valence species. This was also supported by the observed electronic spectra of the complexes. Magnetic susceptibility measurements displayed octahedral geometry around iron in mixed-valence state and a net antiferromagnetic exchange coupling via μ-oxo atom. Trinuclear nature of the complexes was confirmed by their molecular weight determination and FAB mass spectra. A plausible structure for these complexes has been established on the basis of spectral and magnetic moment data.

Spectroscopic studies on some fluorescent mixed-ligand titanium(IV) complexes

A novel route to synthesize some titanium(IV) complexes containing acetylacetone, straight chain carboxylic acid and hydroxycarboxylic acid ligands has been investigated. Complexes with the general formula [Ti(acac)Cl 2− n (OOCR*) n (OOCC 15H 31)] (where Hacac = acetylacetone, R*COOH = hydroxycarboxylic acids and n = 1 or 2) have been isolated and characterized. Molecular weight determinations indicated mononuclear nature of the complexes. LMCT bands were observed in the electronic spectra. Infrared spectra suggested bidentate nature of the ligands. Fluorescent behaviour of the complexes was noticed on the basis of fluorescence spectra. Powder XRD indicated them to be semi-crystalline having the crystallite size in 136–185 nm range. Transmission electron microscopy (TEM) indicated spherical particles of ∼200 nm diameter. On the basis of physico-chemical studies, it is suggested that titanium is having coordination number 7 or 8 in these complexes.