Compounds In Gas Phase Research Articles

Toward high value sensing: monolayer-protected metal nanoparticles in multivariable gas and vapor sensors.

For detection of gases and vapors in complex backgrounds, "classic" analytical instruments are an unavoidable alternative to existing sensors. Recently a new generation of sensors, known as multivariable sensors, emerged with a fundamentally different perspective for sensing to eliminate limitations of existing sensors. In multivariable sensors, a sensing material is designed to have diverse responses to different gases and vapors and is coupled to a multivariable transducer that provides independent outputs to recognize these diverse responses. Data analytics tools provide rejection of interferences and multi-analyte quantitation. This review critically analyses advances of multivariable sensors based on ligand-functionalized metal nanoparticles also known as monolayer-protected nanoparticles (MPNs). These MPN sensing materials distinctively stand out from other sensing materials for multivariable sensors due to their diversity of gas- and vapor-response mechanisms as provided by organic and biological ligands, applicability of these sensing materials for broad classes of gas-phase compounds such as condensable vapors and non-condensable gases, and for several principles of signal transduction in multivariable sensors that result in non-resonant and resonant electrical sensors as well as material- and structure-based photonic sensors. Such features should allow MPN multivariable sensors to be an attractive high value addition to existing analytical instrumentation.

Transition Metal Complexes with Tridentate Ligand: Preparation, Spectroscopic Characterization, Thermal Analysis and Structural Studies

New series of metal ions complexes have been prepared from the new ligand 1,5- Dimethyl-4- (5-oxohexan-2- ylideneamino) -2-phenyl- 1H-pyrazol-3 (2H)-one derived from 2,5-hexandione and 4-aminophenazone. Then, its V(IV), Ni(II), Cu(II), Pd(II), Re(V) and Pt(IV) complexes prepared. The compounds have been characterized by FT-IR, UV-Vis, mass and 1H and 13C-NMR spectra, TGA curve, magnetic moment, elemental microanalyses (C.H.N.O.), chloride containing, Atomic absorption and molar conductance. Hyper Chem-8 program has been used to predict structural geometries of compounds in gas phase, the heat of formation, (binding, total and electronic energy) and dipole moment at 298 K.

Diphenolic acid based biphosphate on the properties of polylactic acid: Synthesis, fire behavior and flame retardant mechanism

In an effort to impart fire protection properties to polylactic acid (PLA) utilizing renewable resources, diphenolic acid, a plant derived compound, was used to synthesize a biphosphate (hereinafter shortened as FR) that contains two types of phosphorus. The chemical structure of FR was confirmed by 1H NMR and 31P NMR. UL-94 V0 rating and LOI value of 27.4 for PLA were achieved at the FR loading content of 16 wt%. Besides, the heat release rate and total heat release of the flame retardant PLA were decreased remarkably in cone calorimetric tests. The significantly increased CO/CO2 ratio in cone tests and the presence of phosphorous containing compound in gas phase in TG-FTIR tests confirmed that the gas phase mechanism is mainly responsible for the improved flame retardant performance. Differential scanning calorimetric analysis showed the glass transition temperature of PLA composites have no change indicating no plasticizing effect of the FR. Finally, the tensile tests revealed that the ductility of PLA was sustained and tensile strength was depressed in a minimal content after the FR was incorporated. This work suggests a novel green strategy for improving flame retardancy performance of PLA and promoting the utilization of sustainable resource.

Microwave-assisted synthesis of 4-(2,2'-bithiophen-5-yl)-5-phenylpyrimidine derivatives as sensors for detection of nitroaromatic explosives

A reaction sequence involving microwave-assisted Suzuki cross-coupling steps and bromination with N-bromosuccinimide was used to synthesize 4-{4-[4',5'-bis(4-diphenylaminophenyl)-3'-hexyl-2,2'-bithiophen-5-yl]pyrimidin-5-yl}benzonitrile. The optical properties of the obtained compound were studied to evaluate it for possible applications as a sensor of nitroaromatic compounds in acetonitrile solutions and gas phase.

Synthesis, crystal structure, biomolecular interactions and anticancer properties of Ni(II), Cu(II) and Zn(II) complexes bearing S-allyldithiocarbazate

A new series of bivalent Ni(II), Cu(II) and Zn(II) metal complexes containing Schiff base ligand [H-emk-sadtc] [(E)-allyl 2-(butan-2-ylidene) hydrazine carbodithioate)] were synthesized and characterized by different spectroscopic techniques. The molecular structure of the ligand and its complexes 1 [(E)-allyl 2-(butan-2-ylidene) hydrazine carbodithioato nickel(II)], complex 2 [(E)-allyl 2-(butan-2-ylidene) hydrazine carbodithioato copper(II)], complex 3 [(E)-allyl 2-(butan-2-ylidene) hydrazine carbodithioato zinc(II)] were confirmed by single crystal X-ray crystallography. XRD data of the complexes had revealed a distorted square planar geometry around the metal ion, satisfied by N2S2 fashion. Density functional calculations of all the compounds in gas phase were performed by using DFT (B3LYP) with 6-311G basis set. The calculated FT-IR and structural data are in good agreement with the experimental results and confirmed by the experimental one. The interactions of calf thymus (CT) DNA and bovine serum albumin (BSA) with complexes 1–3 were explored by emission spectra. Catecholase and phosphatase-like activities of all the complexes were also investigated. An in vitro cytotoxicity study of the complexes had shown significant activity against human cervical cancer cell line (HeLa) with the best results of complex 2, which was found to be more toxic to cancer cells with a few micromolar concentrations, as the IC50 value, but significantly less toxic to normal cell lines. Additionally, the cell death analysis was carried out by AO/EB and DAPI staining methods.

Gas/solid carbon branching ratios in surface-mediated reactions and the incorporation of carbonaceous material into planetesimals.

We report the ratio of the initial carbon available as CO that forms gas-phase compounds compared to the fraction that deposits as a carbonaceous solid (the gas/solid branching ratio) as a function of time and temperature for iron, magnetite, and amorphous iron silicate smoke catalysts during surface-mediated reactions in an excess of hydrogen and in the presence of N2. This fraction varies from more than 99% for an amorphous iron silicate smoke at 673 K to less than 40% for a magnetite catalyst at 873 K. The CO not converted into solids primarily forms methane, ethane, water, and CO2, as well as a very wide range of organic molecules at very low concentration. Carbon deposits do not form continuous coatings on the catalytic surfaces, but instead form extremely high surface area per unit volume "filamentous" structures. While these structures will likely form more slowly but over much longer times in protostellar nebulae than in our experiments due to the much lower partial pressure of CO, such fluffy coatings on the surfaces of chondrules or calcium aluminum inclusions could promote grain-grain sticking during low-velocity collisions.

Preparation and Spectroscopic Studies of Some Metal Ion Complexes of 2-((4-Formyl-3-Hydroxynaphthalen-2-yl) Diazenyl) Benzoic Acid

New azo ligand 2-((4-formyl-3-hydroxynaphthalen-2-yl) diazenyl) benzoic acid (H2L) was synthesized from the reaction of 2-aminobenzoic acid and2-hydroxy-1-naphthaldehyde. Monomeric complexes of this ligand, of general formulae [MII(L)(H2O)] with (MII = Mn, Co, Ni, Cu, Zn, Pd, Cd and Hg ) were reported. The compounds were isolated and characterized in solid state by using 1H-NMR, FT-IR, UV–Vis and mass spectral studies, elemental microanalysis, metal content, magnetic moment measurements, molar conductance and chloride containing. These studies revealed tetrahedral geometries for all complexes except PdII complex is Square planar. The study of complexes formation via molar ratio of (M:L) as (1:1). Theoretical treatments of compounds in gas phase were studied using Hyper Chem-8 program has.

A chamber study on the reactions of O3, NO, NO2 and selected VOCs with a photocatalytically active cementitious coating material.

Chamber studies were performed to investigate the efficiency of a photocatalytically active cementitious coating material to depollute contaminated air. The results showed a photocatalytic effect on ozone (O3), proven by an increase of the geometric uptake coefficient from 5.2 × 10(-6) for the inactive to 7.7 × 10(-6) for the active material under irradiation. Measured first-order rate constants for nitrogen oxides (NOx) under irradiation are in the range of 2.6-5.9 × 10(-4)s(-1), which is significantly higher compared to the inactive material (7.3-9.7 × 10(-5)s(-1)) demonstrating the photocatalytic effect. However, no significant photocatalytic degradation was observed for the studied volatile organic compounds (VOCs) toluene and isoprene resulting in only an upper limit uptake coefficient of 5.0 × 10(-7) for both VOCs. In all experiments using the photocatalytically active material, a clear formation of small carbonyl (C1-C5) gas phase compounds was identified which is suggested to result from the photocatalytic degradation of organic additives. In contrast to the uptake observed for pure O3, during the experiments with NOx (≥50% relative humidity), a clear photocatalytic formation of O3 was observed. For the material investigated, an empirically derived overall zero-order rate constant of k 0 (O3) ≈ 5 × 10(7)moleculescm(-3)s(-1) was determined. The results demonstrate the necessity of detailed studies of heterogeneous reactions on such surfaces under more complex simulated atmospheric conditions as enabled by simulation chambers.

Modeling and measurements of urban aerosol processes on the neighborhood scale in Rotterdam, Oslo and Helsinki

Abstract. This study evaluates the influence of aerosol processes on the particle number (PN) concentrations in three major European cities on the temporal scale of 1 h, i.e., on the neighborhood and city scales. We have used selected measured data of particle size distributions from previous campaigns in the cities of Helsinki, Oslo and Rotterdam. The aerosol transformation processes were evaluated using the aerosol dynamics model MAFOR, combined with a simplified treatment of roadside and urban atmospheric dispersion. We have compared the model predictions of particle number size distributions with the measured data, and conducted sensitivity analyses regarding the influence of various model input variables. We also present a simplified parameterization for aerosol processes, which is based on the more complex aerosol process computations; this simple model can easily be implemented to both Gaussian and Eulerian urban dispersion models. Aerosol processes considered in this study were (i) the coagulation of particles, (ii) the condensation and evaporation of two organic vapors, and (iii) dry deposition. The chemical transformation of gas-phase compounds was not taken into account. By choosing concentrations and particle size distributions at roadside as starting point of the computations, nucleation of gas-phase vapors from the exhaust has been regarded as post tail-pipe emission, avoiding the need to include nucleation in the process analysis. Dry deposition and coagulation of particles were identified to be the most important aerosol dynamic processes that control the evolution and removal of particles. The error of the contribution from dry deposition to PN losses due to the uncertainty of measured deposition velocities ranges from −76 to +64 %. The removal of nanoparticles by coagulation enhanced considerably when considering the fractal nature of soot aggregates and the combined effect of van der Waals and viscous interactions. The effect of condensation and evaporation of organic vapors emitted by vehicles on particle numbers and on particle size distributions was examined. Under inefficient dispersion conditions, the model predicts that condensational growth contributes to the evolution of PN from roadside to the neighborhood scale. The simplified parameterization of aerosol processes predicts the change in particle number concentrations between roadside and urban background within 10 % of that predicted by the fully size-resolved MAFOR model.

Distribution of legacy and emerging semivolatile organic compounds in five indoor matrices in a residential environment

Seven types of indoor samples, covering five indoor matrices, were collected in a residential room, and analyzed for five classes of semivolatile organic compounds (SVOCs). The goal was to improve the understanding of the relationship between indoor air, surface films and dust, based on differences in sources, physicochemical properties, and indoor environmental characteristics. Comparisons of the five matrices (gas- and particle-phase air, floor dust, surface dust/films and window films) demonstrated that within our test room a semi-quantitative measurement of the SVOC distributions and concentrations could be obtained by air, and composite dust or furniture surface wipes. Dust concentrations varied within the room, and spot samples were not necessarily representative of the average room conditions.Polyurethane foam passive air samplers (PUF-PAS) successfully quantified the total air concentrations of the studied SVOC compound groups, as indoor air concentrations were dominated by gas-phase compounds, however air concentrations of individual particle-bound compounds had higher uncertainty. Measured concentrations of dust/surfaces could be used to estimate air concentrations of legacy SVOCs, demonstrating equilibrium in the room. However, air concentrations of current-use compounds (flame retardants, polycyclic aromatic hydrocarbons (PAHs)) could not be estimated from dust/surface concentrations, demonstrating the influence of ongoing primary emissions and non-equilibrium status in the room.

What do correlations tell us about anthropogenic–biogenic interactions and SOA formation in the Sacramento plume during CARES?

Abstract. During the Carbonaceous Aerosols and Radiative Effects Study (CARES) the US Department of Energy (DOE) G-1 aircraft was used to sample aerosol and gas phase compounds in the Sacramento, CA, plume and surrounding region. We present data from 66 plume transects obtained during 13 flights in which southwesterly winds transported the plume towards the foothills of the Sierra Nevada. Plume transport occurred partly over land with high isoprene emission rates. Our objective is to empirically determine whether organic aerosol (OA) can be attributed to anthropogenic or biogenic sources, and to determine whether there is a synergistic effect whereby OA concentrations are enhanced by the simultaneous presence of high concentrations of carbon monoxide (CO) and either isoprene, MVK + MACR (sum of methyl vinyl ketone and methacrolein), or methanol, which are taken as tracers of anthropogenic and biogenic emissions, respectively. Linear and bilinear correlations between OA, CO, and each of three biogenic tracers, “Bio”, for individual plume transects indicate that most of the variance in OA over short timescales and distance scales can be explained by CO. For each transect and species a plume perturbation, (i.e., ΔOA, defined as the difference between 90th and 10th percentiles) was defined and regressions done amongst Δ values in order to probe day-to-day and location-dependent variability. Species that predicted the largest fraction of the variance in ΔOA were ΔO3 and ΔCO. Background OA was highly correlated with background methanol and poorly correlated with other tracers. Because background OA was ∼ 60 % of peak OA in the urban plume, peak OA should be primarily biogenic and therefore non-fossil, even though the day-to-day and spatial variability of plume OA is best described by an anthropogenic tracer, CO. Transects were split into subsets according to the percentile rankings of ΔCO and ΔBio, similar to an approach used by Setyan et al. (2012) and Shilling et al. (2013) to determine if anthropogenic–biogenic (A–B) interactions enhance OA production. As found earlier, ΔOA in the data subset having high ΔCO and high ΔBio was several-fold greater than in other subsets. Part of this difference is consistent with a synergistic interaction between anthropogenic and biogenic precursors and part to an independent linear dependence of ΔOA on precursors. The highest values of ΔO3, along with high temperatures, clear skies, and poor ventilation, also occurred in the high ΔCO–high ΔBio data set. A complicated mix of A–B interactions can result. After taking into account linear effects as predicted from low concentration data, an A–B enhancement of OA by a factor of 1.2 to 1.5 is estimated.

Transition Metal Complexes with Tridentate Ligand: Preparation, Spectroscopic Characterization, Thermal Analysis and Structural Studies

New series of metal ions complexes have been prepared from the new ligand 1,5- Dimethyl-4- (5-oxohexan-2- ylideneamino) -2-phenyl- 1H-pyrazol-3 (2H)-one derived from 2,5-hexandione and 4-aminophenazone. Then, its V(IV), Ni(II), Cu(II), Pd(II), Re(V) and Pt(IV) complexes prepared. The compounds have been characterized by FT-IR, UV-Vis, mass and 1H and 13C-NMR spectra, TGA curve, magnetic moment, elemental microanalyses (C.H.N.O.), chloride containing, Atomic absorption and molar conductance. Hyper Chem-8 program has been used to predict structural geometries of compounds in gas phase, the heat of formation, (binding, total and electronic energy) and dipole moment at 298 K.

Preparation and Spectroscopic Studies of Some Metal Ion Complexes of 2-((4-Formyl-3-Hydroxynaphthalen-2-yl) Diazenyl) Benzoic Acid

New azo ligand 2-((4-formyl-3-hydroxynaphthalen-2-yl) diazenyl) benzoic acid (H2L) was synthesized from the reaction of 2-aminobenzoic acid and2-hydroxy-1-naphthaldehyde. Monomeric complexes of this ligand, of general formulae [MII(L)(H2O)] with (MII = Mn, Co, Ni, Cu, Zn, Pd, Cd and Hg ) were reported. The compounds were isolated and characterized in solid state by using 1H-NMR, FT-IR, UV–Vis and mass spectral studies, elemental microanalysis, metal content, magnetic moment measurements, molar conductance and chloride containing. These studies revealed tetrahedral geometries for all complexes except PdII complex is Square planar. The study of complexes formation via molar ratio of (M:L) as (1:1). Theoretical treatments of compounds in gas phase were studied using Hyper Chem-8 program has.

THE MATRIX EFFECT OF TUNA AND MAHI-MAHI ON BIOGENIC AMINE DETECTION

Method of standard addition (MSA) is used to account for and quantify matrix effect. In this study, MSA was used to analyze the matrix effect of mahi-mahi and tuna in respect to biogenic amine detection. Two different detection methods were used in conjunction with the MSA procedure: a colorimetric strip that detects volatile biogenic amines and a histamine-specific ELISA (enzyme-linked immunosorbant assay), which detects histamine in the liquid phase. Trained sensory experts were utilized to grade mahi-mahi and tuna. The grading system acted as a measure of fish quality. A biogenic amine cocktail was created to act as the standard spike for the MSA procedure. It contained histamine and other biogenic amine compounds of varying volatility that are present in nature. The ELISA-MSA showed a clear correlation between increase in histamine and a lower quality sample (higher numerical grade). The colorimetric strips did not have a clear correlation between biogenic amine content and grade. Comparing the two methods demonstrates that the matrix effect of the tuna and mahi-mahi is likely more prominent with gas phase compounds than liquid phase compounds.

Gas-phase advanced oxidation as an integrated air pollution control technique

Gas-phase advanced oxidation (GPAO) is an emerging air cleaning technology based on the natural self-cleaning processes that occur in the Earth’s atmosphere. The technology uses ozone, UV-C lamps and water vapor to generate gas-phase hydroxyl radicals that initiate oxidation of a wide range of pollutants. In this study four types of GPAO systems are presented: a laboratory scale prototype, a shipping container prototype, a modular prototype, and commercial scale GPAO installations. The GPAO systems treat volatile organic compounds, reduced sulfur compounds, amines, ozone, nitrogen oxides, particles and odor. While the method covers a wide range of pollutants, effective treatment becomes difficult when temperature is outside the range of 0 to 80 °C, for anoxic gas streams and for pollution loads exceeding ca. 1000 ppm. Air residence time in the system and the rate of reaction of a given pollutant with hydroxyl radicals determine the removal efficiency of GPAO. For gas phase compounds and odors including VOCs (e.g. C6H6 and C3H8) and reduced sulfur compounds (e.g. H2S and CH3SH), removal efficiencies exceed 80%. The method is energy efficient relative to many established technologies and is applicable to pollutants emitted from diverse sources including food processing, foundries, water treatment, biofuel generation, and petrochemical industries.

Preparation and Spectroscopic Studies of New Transition Metal Complexes of 1-(2, 2-Dicyclohexylethyl)-3-(1, 5-Dimethyl-3-Oxo-2-Phenyl-2,3- Dihydro-1H-pyrazol-4-ylimino) Indolin-2-One

New tridentate ligand 1-(2, 2-dicyclohexylethyl)-3-(1, 5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylimino)indolin-2-one (L) was synthesized from the reaction of 3-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylimino)indolin-2-one and dicyclohexyl amine. Monomeric complexes of this ligand, of general formulae [VOII(L)(SO4)], [MIII(L)Cl3] with M=CrIII and FeIII, and [MII(L)Cl]Clwith (M = MnII and CoII) are reported. The mode of bonding and overall geometry of the complexes were determined through FT-IR, UV–Vis, and mass spectral studies, magnetic moment measurements, elemental analysis, metal content, chloride containing and molar conductance. These studies revealed octahedral geometries for the FeIII, CrIII complexes, square pyramidal for VO(II) complex and tetrahedral for the MnII and CoII complexes. The study of complexes formation via molar ratio and job method in DMF solution has been investigated and results were consistent to those found in the solid complexes with a ratio of (M:L) as (1:1). Hyper Chem-8 program has been used to predict structural geometries of compounds in gas phase the heat of formation (ΔHf o), binding energy (ΔEb), total energy, electronic energy and dipole moment at 298ok.

TiO2–SiO2 films from organic-free colloidal TiO2 anatase nanoparticles as photocatalyst for removal of volatile organic compounds from indoor air

Different types of TiO2–SiO2 composites in the form of powder or films have been reported as efficient photocatalysts for decomposition of organic compounds in liquid and gas phase. Herein, we report for the first time on the formation of efficient TiO2–SiO2 films made from acidic organic-free colloidal solution of TiO2 anatase nanoparticles (AS) and mesoporous SiO2 (SBA-15) with 100% loading (TiO2: SiO2 molar ratio 1:1) under simple and low cost procedure. AS was prepared from metatitanic acid precursor using a novel, environmentally friendly approach of TiO2 nanoparticles precipitation with NaOH and peptization with HCl. These AS/SBA-15 films, immobilized by brush deposition on glass carriers, showed total decomposition of toluene and 91% decomposition of formaldehyde as model VOCs in gas phase, at room temperature under UVA irradiation in lab-made batch photoreactor. The trend of photocatalytic efficiency for decomposition of formaldehyde was AS/SBA-15>P25>PC500>AS. The adsorption capability of the AS/SBA-15 was higher in comparison to its pure TiO2 analogues (AS, P25, PC500) in case of toluene. Turnover frequency (TOF) of the AS/SBA-15 was approximately six times higher in comparison to its pure TiO2 analogue AS for toluene and formaldehyde. The potential of AS/SBA-15 for the use in air cleaning devices is finally discussed.

Modelling the contribution of biogenic volatile organic compounds to new particle formation in the Jülich plant atmosphere chamber

Abstract. We used the Aerosol Dynamics gas- and particle-phase chemistry model for laboratory CHAMber studies (ADCHAM) to simulate the contribution of BVOC plant emissions to the observed new particle formation during photooxidation experiments performed in the Jülich Plant-Atmosphere Chamber and to evaluate how well smog chamber experiments can mimic the atmospheric conditions during new particle formation events. ADCHAM couples the detailed gas-phase chemistry from Master Chemical Mechanism with a novel aerosol dynamics and particle phase chemistry module. Our model simulations reveal that the observed particle growth may have either been controlled by the formation rate of semi- and low-volatility organic compounds in the gas phase or by acid catalysed heterogeneous reactions between semi-volatility organic compounds in the particle surface layer (e.g. peroxyhemiacetal dimer formation). The contribution of extremely low-volatility organic gas-phase compounds to the particle formation and growth was suppressed because of their rapid and irreversible wall losses, which decreased their contribution to the nano-CN formation and growth compared to the atmospheric situation. The best agreement between the modelled and measured total particle number concentration (R2 > 0.95) was achieved if the nano-CN was formed by kinetic nucleation involving both sulphuric acid and organic compounds formed from OH oxidation of BVOCs.

Spatial Variation of Aerosol Chemical Composition and Organic Components Identified by Positive Matrix Factorization in the Barcelona Region.

The spatial distribution of PM1 components in the Barcelona metropolitan area was investigated using on-road mobile measurements of atmospheric particle- and gas-phase compounds during the DAURE campaign in March 2009. Positive matrix factorization (PMF) applied to organic aerosol (OA) data yielded 5 factors: hydrocarbon-like OA (HOA), cooking OA (COA), biomass burning OA (BBOA), and low volatility and semivolatile oxygenated OA (LV-OOA and SV-OOA). The area under investigation (∼500 km(2)) was divided into six zones (city center, harbor, industrial area, precoastal depression, 2 mountain ranges) for measurements and data analysis. Mean zonal OA concentrations are 4.9-9.5 μg m(-3). The area is heavily impacted by local primary emissions (HOA 14-38%, COA 10-18%, BBOA 10-12% of OA); concentrations of traffic-related components, especially black carbon, are biased high due to the on-road nature of the measurements. The formation of secondary OA adds more than half of the OA burden outside the city center (SV-OOA 14-40%, LV-OOA 17-42% of OA). A case study of one measurement drive from the shore to the precoastal mountain range furthest downwind of the city center indicates the importance of nonfossil over anthropogenic secondary OA based on OA/CO.

Synthesis, Characterization, Thermal Analysis and Structural Studies of New Complexes with Tetradentate Ligand

Some new complexes of 4-(5-(1,5-dimethyl-3-oxo-2-phenyl pyrazolidin-4- ylimino)-3,3-dimethyl cyclohexylideneamino) -1,5- dimethyl-2- phenyl -1H- pyrazol -3(2H) –one (L) with Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Pd(II), Re(V) and Pt(IV) were prepared. The ligand and its metal complexes were characterized by phisco- chemical spectroscopic techniques. The spectral data were suggested that the (L) as a neutral tetradentate ligand is coordinated with the metal ions through two nitrogen and two oxygen atoms. These studies revealed Octahedral geometries for all metal complexes, except square planar for Pd(II) complex. Moreover, the thermodynamic activation parameters, such as ?E*, ?H, ?S, ?G and K are calculated from the TGA curves using Coats –Redfern method. Hyper Chem -8 program has been used to predict structural geometries for compounds in gas phase. The heat of formation (?Hf) and bin ding energy (?Eb) at 298 °K for the free ligand and its metal complexes were calculated by PM3 method. The synthesized ligands and their metal complexes were screened for their biological activity against bacterial species, two Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa).