Molecular Geometry Optimization Research Articles

DFT-Based Prediction of Anti-Leishmanial Activity of Carboxylates and Their Antimony(III) Complexes Against Five Leishmanial Strains

Carboxylates and their antimony(III) complexes experimentally scanned earlier for anti-leishmanial activity (IC50) against five leishmanial strains viz., L. major, L. major (Pak), L. tropica, L. mex mex, and L. donovani. These activities have been theoretically predicted by DFT method along with quantitative structure-activity relationship (QSAR) study. Molecular modeling and geometry optimization of the all the eight compounds have been performed on workspace program of CAChe Pro software of Fujitsu by opting B88-PW91 (Becke '88; Perdew & Wang '91) GGA (generalized-gradient approximation) energy functional with DZVP (double-zeta valence polarized ) basis set in DFT (Density Functional Theory). For QSAR, multiple linear regression (MLR) analysis has been performed on Project Leader Program associated with CAChe. The reliability of correlation between experimental activities and predicted activities are r2 = 0.826, r2CV = 0.426 (L. major); r2 = 0.905, r2CV = 0.507 (L. major (Pak)); r2 = 0.980, r2CV = 0.932 (L. tropica); r2 = 0.781, r2CV = 0.580 (L. mex mex) and r2 = 0.634, r2CV = 0.376 (L. donovani), and a comparison of the experimental values and the values obtained by theoretical calculations has been presented pictorially that shows close resemblance.

Electronic transport properties of compressed and stretched helicene-graphene nanostructures, a theoretical study

We present our ab initio simulations of strained helicene molecular junction. First, we present ab-initio models of [n]helicenes up to [100]helicene done by two different recent reactive force field molecular geometry optimization methods (ReaxFF CHOCsKNaClIFLi, 2019 and CHONSMgPNaCuCl, 2018). We used the [4]helicene and [10]helicene models for Density Functional Theory (DFT) electronic transport calculations of various graphene-helicene-graphene molecular junction configurations on Local Density Approximation (LDA) or Generalized Gradient Approach (GGA) level of exchange and correlation energy with Perdew-Zinger (PZ) or Perdew–Burke–Ernzerhof (PBE) functionals and Grimme DFT-D3 van der Waals correction. The electronic transport properties are studied by using of the Green's functions formalism. The electron transmissions and densities of states of [4]helicene (and [10]helicene) attached as a molecular junction in three different configurations to zigzag graphene nanoribbon (ZGNR) electrodes of three different widths were obtained. The structures are analyzed while relaxed, compressed or stretched. The current-voltage and current-strain characteristics are presented and results are compared and discussed. The work is supported by a short review summarizing some of the recent studies related to graphene, helicene, and molecular junctions under strain.

Nonlinear optical properties and optimization strategies of D-π-A type phenylamine derivatives in the near-infrared region

Modifying simple molecular structures to significantly improve nonlinear optical (NLO) performance is a primary prerequisite for scientific research. Based on the four phenylamine derivatives reported in previous studies, we designed four organic nonlinear molecules by changing the acceptor group and π-linker. (Time-dependent) density functional theory (DFT/TD-DFT) was performed on molecular geometry optimization, the contribution of π electrons to the bond order, linear and two-photon absorption (TPA) spectra, the intra-molecular charge transfer matrix (CTM), and NLO coefficients. These aspects were considered to analyze in detail how the structural modification of acceptors and π-linkers affects NLO characteristics. The three modification methods were: adding a carbonyl group at the junction of the π-linker and the acceptor group, adding a carbonyl group and a nitrogen atom to the acceptor group, and replacing the quinolinone with a pyrenyl group as the π-linker. The latter two methods can significantly reduce the excitation energy and enhance the intensity of intra-molecular charge transfer during the two-photon transition. The maximum TPA cross-sections and wavelengths of the designed molecules are DPPM (84722.6 GM, 815.7 nm) and DDPM (21600.6 GM, 781.3 nm). These two molecules have large TPA cross-sections in the near-infrared region, which renders them as possible NLO materials with broad application prospects.

Contrasting solution-state properties within a family of amyloid-binding molecular tools

Rational modification to the molecular structure of a family of amyloid-binding bifunctional molecular tools improves their hydrophilicity and aqueous solubility, yet raises questions about self-aggregation. Bifunctional organic molecules enable chemists to design and build molecules that have a wide variety of emergent functional properties. While the majority of these compounds are designed to bind to proteins, this work focuses on those that can bind to amyloid fibrils. These molecular tools can add new functional properties to the fibrils by delivering functional molecular cargo to their surfaces. Second generation tools, which have redesigned amyloid-binding and linker regions, are presented herein. Solubility measurements and partition experiments show that these changes enable the new compounds to dissolve better in pH 7.4 buffered water, which is the natural solvent in which they are most likely to find use and application. One of these compounds, however, contrasts to the others in that it self-associates in DMSO solution. This self-association can be seen experimentally by NMR broadening and fluorescence auto-quenching. An enhanced understanding of how the structural details of these compounds cause this undesired self-association will aid the subsequent development of highly useful amyloid-targeting bifunctional molecules. Herein, several molecular dynamics simulations and DFT geometry optimizations are used to evaluate multiple hypotheses about the nature of the observed self-association.

Crystal structure and optoelectronic properties of a supramolecular chlorobismuthate salt templated with 4-pyridiniumthioamide

The organic-inorganic hybrid material with formula (C6H7N2S)2[BiCl6].H2O is synthesized at room temperature by slow evaporation method. It crystallizes in the monoclinic symmetry, space group P21/m, with the following parameters a = 8.2832 (9) Å, b = 16.1576 (16)Å, c = 8.9272 (9)Å, β= 108.571 (6)° Z = 2 and V = 1132.6 (2)Å3. However, the supramolecular structure is built from the mineral entities: hexachlorobismuthate (III) complex [BiCl6]3−, chloride atom anion and free water molecule, which are linked together and to the organic protonated 4-pyridinethioamide molecule by hydrogen bonds only, to form a zero dimensional network. The Hirshfeld analysis results show that in all potential molecular contacts, the H…Cl/Cl…H constitutes the most important interaction in the crystal (44.2 %). Vibrational spectroscopy analysis confirm the existence of vibrational modes that correspond to the protonated 4-pyridinethioamide molecule as an organic part in the material. Computational details of the molecular geometry optimization and calculation by DFT method show that the energy gap ∆ELUMO–HOMO is found to be 1.87 eV into the hybrid compound. Finally, photoluminescence measurement indicates that the synthesized material manifests luminescence property in its solid state.

Synthesis, Molecular Docking and DFT Studies of Biologically Active N-((3-(4-Nitrophenyl)-1-phenyl-1H-pyrazol-4-yl)methylene)aniline Derivatives

Some biologically active pyrazole clubbed imino molecules have been designed and synthesized from 1-phenyl-3-nitro phenyl-1H- pyrazol-4-carboxaldehyde and substituted aromatic amines via acid catalyzed condensation reaction. All the synthesized molecules were characterized by IR, 1H NMR, 13C NMR and mass spectral techniques. The in vitro antibactericidal property of the synthesized compounds was screened and compared with the results of theoretical molecular docking. Optimization of molecular geometry, DNA binding interaction and FMO analysis were also investigated by computational studies using Gaussian 16 package at B3LYP/6-31G(d,p) level. All the synthesized compounds exhibited moderate to good biological activities both experimentally and theoretically.

Effects of inorganic substitutions on electronic transport properties of single-molecule devices

The actual fabrication and integration of single organic molecular devices face several challenges, which is precisely the advantages of conventional inorganic technology. Therefore, it is interesting to investigate the device performance of organic molecules with inorganic substitutions. Based on a combined density functional theory for the optimization of molecular geometries and calculation of electronic properties, with the non-equilibrium Green’s function for the simulation of electronic transport properties, the present work studies the performance of group III and V substituted benzene, i.e., XnB3−nN3H6 (X = Al, Ga; n = 0 − 3) molecules/clusters, sandwiched between two gold electrodes. The results suggest that, compared with the electronic transport properties of benzene molecular device, with the index n increases, a worse device performance will be observed. These phenomena will provide a new direction for future design of molecular devices.

DFT Analysis of Ions Conductivity of Proline in Certain Solvents: Calculation of Association Parameters

Proline (Pro.) is non-essential amino acid, and it is from the amino acids which the human’s body can synthesize it, from L-glutamate. It is studied in the temp. range from 288.16 to 313.16 K at 5 K by conductivities in H2O, and methanol. The Kohlrausch equations was used to find out pattern of electrolyte, the curve indicate pro. was weakly associated in various temperatures and solvents. The Lee-Wheaton equation was us to calculation the Equivalent conductance at infinite dilution (Λο), The association constant (Ka) and distance parameter (R). The values of (Λο), (Ka), and (R) differ from solvent to another depending on the interactions in solution. The molecular modeling, geometry optimization and characterization of pro. has been performed using semi empirical method, and all theoretical parameters was calculated by using Austin Model 1 (AM1), and used density functional theory (DFT) B3LYP method by using 6-311G bases set.

Synthesis, spectroscopic, DFT, and molecular docking studies on 1,4-dihydropyridine derivative compounds: a combined experimental and theoretical study.

Dihydropyridines are the most extensively used drugs in the treatment of hypertension. Nifedipine is the prototype of calcium channel blocker. The dihydropyridine derivative compounds of diethyl 4-(4-bromophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (DHPB), diethyl 4-(furan-2yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (DHPF), and diethyl-4-phenyl-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (DHPP) were synthesized using the Hantzsch reaction. The DFT/B3LYP exchange-correlation function was employed to perform quantum chemical calculations such as molecular geometry optimization, vibrational analysis, frontier molecular orbital (FMO), molecular electrostatic potential (MEP), natural bond order (NBO), global reactive descriptors, and Fukui functions to determine the structural characteristics related to biological activity of the compounds. The molecular docking and molecular dynamics were employed to study the binding interaction and stability of protein-ligand complex in the docked site.

Synthesis, crystallization, XRD, Hirshfeld surface, vibrational spectra, and quantum chemical studies and Computational investigation of Caffeinium bisulfate: a new noncentrosymmetric form

Crystals of caffienium bisulfate were grown by solution growth technique. The vibrational spectra were scaled by adopting FT-IR and FT-Raman spectroscopy with the wide range, between 4000-400 cm−1. X-ray diffraction study exhibited that the functional group such as N-H….O hydrogen bonds played an effective role in generating hydrogen-bonded crystal packing, pre-dominant. The examined molecules showed an interconnection of anions, by the O-H…O hydrogen bonds, establishing a chain C (4) motif, extending along the b-axis of the unit cell. Further, anions have shown interaction with cations, through N-H…O hydrogen bond, resulting from a ring R1 2 (4) motif. The formed ring and chain motifs manifested an alternate hydrophilic stratum at z = ¼ and ¾. Geometrical optimization of tester molecule was done with Density Functional Theory (DFT) employing B3LYP function along with Hartree-Fock (HF) using 6-311++G(d,p) level basis set. Optimum molecular geometry and calculated database on the vibrational spectra were critically analyzed by comparing with experimental findings, resulting in a good correlating exhibited among them. Natural Bond Orbital (NBO) study revealed that hyper conjugation affinities and intermolecular charge transfer (ICT). An advanced technique such as HOMO-LUMO plot was performed to understand the chemical hardness, electro negativity and chemical efficacy of the tested molecules. The results showed that the occurrence of lower band gap value in the frontier orbital was responsible for the possible biological activities of the study materials. Bioinformatics analysis is applied for analyzing the biological activity of CAFSUL against Alzheimer's disease through computational methods. Communicated by Ramaswamy H. Sarma

Analytic Energy Gradients for the Driven Similarity Renormalization Group Multireference Second-Order Perturbation Theory.

We derive analytic energy gradients of the driven similarity renormalization group (DSRG) multireference second-order perturbation theory (MRPT2) using the method of Lagrange multipliers. In the Lagrangian, we impose constraints for a complete-active-space self-consistent-field reference wave function and the semicanonical orthonormal molecular orbitals. Solving for the associated Lagrange multipliers is found to share the same asymptotic scaling of a single DSRG-MRPT2 energy computation. A pilot implementation of the DSRG-MRPT2 analytic gradients is used to optimize the geometry of the singlet and triplet states of p-benzyne. The equilibrium bond lengths and angles are similar to those computed via other MRPT2s and Mukherjee's multireference coupled cluster theory. An approximate DSRG-MRPT2 method that neglects the contributions of the three-body density cumulant is found to introduce negligible errors in the geometry of p-benzyne, lending itself to a promising low-cost approach for molecular geometry optimizations using large active spaces.

Single-Crystal Investigation, Hirshfeld Surface Analysis, and DFT Study of Third-Order NLO Properties of Unsymmetrical Acyl Thiourea Derivatives

In the current research work, unsymmetrical acyl thiourea derivatives, 4-((3-benzoylthioureido)methyl)cyclohexane-1-carboxylic acid (BTCC) and methyl 2-(3-benzoylthioureido)benzoate (MBTB), have been synthesized efficiently. The structures of these crystalline thioureas were unambiguously confirmed by single-crystal diffractional analysis. The crystallographic investigation showed that the molecular configuration of both compounds is stabilized by intramolecular N–H···O bonding. The crystal packing of BTCC is stabilized by strong N–H···O bonding and comparatively weak O–H···S, C–H···O, C–H···π, and C–O···π interactions, whereas strong N–H···O bonding and comparatively weak C–H···O, C–H···S, and C–H···π interactions are responsible for the crystal packing of MBTB. The noncovalent interactions that are responsible for the crystal packing are explored by the Hirshfeld surface analysis for both compounds. The void analysis is performed to find the quantitative strength of crystal packing in both compounds. Additionally, state-of-the-art applied quantum chemical techniques are used to further explore the structure–property relationship in the above-entitled molecules. The optimization of molecular geometries showed a reasonably good correlation with their respective experimental structures. Third-order nonlinear optical (NLO) polarizability calculations were performed to see the advanced functional application of entitled compounds as efficient NLO materials. The average static γ amplitudes are found to be 27.30 × 10–36 and 102.91 × 10–36 esu for the compounds BTCC and MBTB, respectively. The γ amplitude of MBTB is calculated to be 3.77 times larger, which is probably due to better charge-transfer characteristics in MBTB. The quantum chemical analysis in the form of 3-D plots was also performed for their frontier molecular orbitals and molecular electrostatic potentials for understanding charge-transfer characteristics. We believe that the current investigation will not only report the new BTCC and MBTB compounds but also evoke the interest of the materials science community in their potential use in NLO applications.

Variational quantum algorithm for molecular geometry optimization

Classical algorithms for predicting the equilibrium geometry of strongly correlated molecules require expensive wave function methods that become impractical already for few-atom systems. In this work, we introduce a variational quantum algorithm for finding the most stable structure of a molecule by explicitly considering the parametric dependence of the electronic Hamiltonian on the nuclear coordinates. The equilibrium geometry of the molecule is obtained by minimizing a more general cost function that depends on both the quantum circuit and the Hamiltonian parameters, which are simultaneously optimized at each step. The algorithm is applied to find the equilibrium geometries of the ${\mathrm{H}}_{2},$ ${\mathrm{H}}_{3}{}^{+},$ ${\mathrm{BeH}}_{2},$ and ${\mathrm{H}}_{2}\mathrm{O}$ molecules. The quantum circuits used to prepare the electronic ground state for each molecule were designed using an adaptive algorithm where excitation gates in the form of Givens rotations are selected according to the norm of their gradient. All quantum simulations are performed using the PennyLane library for quantum differentiable programming. The optimized geometrical parameters for the simulated molecules show an excellent agreement with their counterparts computed using classical quantum chemistry methods.

Designing small organic non-fullerene acceptor molecules with diflorobenzene or quinoline core and dithiophene donor moiety through density functional theory

The non-fullerene acceptors A1–A5 with diflourobenzene or quinoline core (bridge) unit, donor cyclopenta[1,2-b:3,4-b′]dithiophene unit and 2-(2-methylene-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile as acceptor unit with additional phenyl, fulvene or thieno[3,2-d]pyrimidinyl 5-oxide groups have been designed through DFT calculations. The optimization of molecular geometries were performed with density functional theory (DFT) at B3LYP 6-31G (d,p) level of theory. The frontier molecular orbital (FMO) energies, band gap energies and dipole moments (ground and excited state) have been calculated to probe the photovoltaic properties. The band gap (1.42–2.01 eV) and dipole moment values (5.5–18. Debye) showed that these designed acceptors are good candidates for organic solar cells. Time-Dependent Density Functional Theory (TD-DFT) results showed λmax (wave length at maximum absorption) value (611–837 nm), oscillator strength (f) and excitation energies (1.50–2.02 eV) in gas phase and in CHCl3 solvent (1.48–1.89 eV) using integral equation formalism variant (IEFPCM) model. The λmax in CHCl3 showed marginal red shift for all designed acceptors compared with gas phase absorption. The partial density of states (PDOS) has been plotted by using multiwfn which showed that all the designed molecules have more electronic distribution at the donor moiety and lowest at the central bridge. The reorganization energies of electron (λe) (0.0007 eV to 0.017 eV), and the hole reorganization energy values (0.0003 eV to − 0.0403 eV) were smaller which suggested that higher charged motilities. The blends of acceptors A1–A5 with donor polymer D1 provided open circuit voltage (Voc) and ∆HOMO off-set of the HOMO of donor and acceptors. These blends showed 1.04 to 1.5 eV values of Voc and 0 to 0.38 eV ∆HOMO off set values of the donor–acceptor bends which indicate improved performance of the cell. Finally, the blend of D1–A4 was used for the study of distribution of HOMO and LUMO. The HOMO were found distributed on the donor polymer (D1) while the A4 acceptor was found with LUMO distribution. Based on λmax values, and band gap energies (Eg), excitation energies (Ex), reorganization energies; the A3 and A4 will prove good acceptor molecules for the development of organic solar cells.

New Compound of Pyridine-4-Boronic Acid Cation and Pt(CN)4 Anion Salt: Synthesis, Structural Properties, Hirshfeld Surface Analysis and Density Functional Theory Calculations

In this work, the novel compound [HNC5H4B(OH)2-4][Pt(CN)4] (1) has been synthesized and structurally characterized. The compound (1) crystallizes in monoclinic, space group P21/c, a=5.6159(11) Å, b=14.656(3) Å, c=11.619(2) Å, 𝛼=90, β= 110.35(3), γ=90, V= 896.6(3) Å3, Z=2. The optimum molecular geometry parameters have been investigated with the DFT/B3LYP method. All geometric parameters are found in good agreement with crystallographic and computational results. Contributions of fragments molecular orbitals (HOFO-LUFO) to frontier molecular orbitals (HOMOLUMO) are calculated charge transferred from Pt moiety to other fragments.

Synthesis, spectral characterization and biological evaluations with DFT analysis on molecular geometry and NLO of 1,4,7,10-tetraazacyclotetradecane-11,14-dione

A novel 14-membered tetradentate N4 macrocyclic ligand, STETA (1,4,7,10-tetraazacyclotetradecane-11,14-dione) was synthesized by [1+1] cyclic condensation of succinic acid with triethylenetetramine through reflux method in ethanolic solvent. The synthesized macrocyclic ligand was experimentally characterized by C H N analysis, FT-IR, FT-Raman, electronic, 1H NMR, 13C NMR and ESI MS. Optimization of molecular geometry and spectral (FT-IR, FT-Raman, 1H/13C NMR) analysis of STETA were performed by employing DFT with B3LYP/6-311+G(d) basis set and computational results were correlated with experimental (NMR, IR, Raman) spectral values. Electronic absorption properties of STETA were monitored using TD-DFT approach and also theoretical UV–vis results were experimentally compared. FMO analysis, MEP plot, global reactivity descriptors, first-order hyperpolarizability and NBO analysis were rationalized on the ground of DFT computation. NLO activity of title molecule was confirmed by both molecular hyperpolarizability calculations and SHG measurements. In vitro antibacterial activity and DPPH radical scavenging effects of STETA were screened.

Crystal structure, Hirshfeld surface analysis and DFT studies of N-(4-acetylphenyl)quinoline-3-carboxamide

Crystalline organic compound, N-(4-acetylphenyl)quinoline-3-carboxamide (4) was readily prepared using our previously reported experimental procedure by the reaction of quinoline-3-carboxylic acid (1) with thionyl chloride to generate the acid chloride in situ followed by the coupling itself with 4-aminoacetophenone (3). This report describes the in-depth structural analysis thereof. The spectral characterization was done using FT-IR, 1H-NMR, 13C-NMR and UV-Vis spectroscopy, while its 3D-structure confirmed unambiguously by single crystal X-ray diffraction. The title compound crystallizes in the monoclinic system with the P21/c space group, Z = 4. The crystal packing is mainly controlled by N–H•••O, and C–H•••O hydrogen bond interactions. Molecular geometry optimizations were conducted using the DFT method at the B3LYP/6-31G+(d,p) level of theory and the theoretical UV-Vis spectrum was found to be in good agreement with the experimental spectrum.

DFT-Based Study of Physical, Chemical and Electronic Behavior of Liquid Crystals of Azoxybenzene Group: <i>p</i>-azoxyanisole, <i>p</i>-azoxyphenetole, ethyl-<i>p</i>-azoxybenzoate, ethyl-<i>p</i>-azoxycinnamate and <i>n</i>-octyl-<i>p</i>-azoxycinnamate

The present work describes the geometry and electronic structures of liquid crystals of azoxybenzene group and their reactivity with respect to molecular properties: total energy, ionization potential, electron affinity, HOMO energy, LUMO energy, electronegativity, hardness and dipole moment. Literature shows that mesomorphism depends particularly on the nature of terminal groups and their linkages with parent molecule. And thus substitution of terminal groups can help to fine tune the liquid crystal behavior and also their applications. In this work the effect of four terminal groups of same and diverse nature has been studied. For the study, the molecular modeling and geometry optimization of the compounds have been performed on workspace program of CAChe Pro 5.04 software of Fujitsu using DFT method.

Nuclear-electronic orbital methods: Foundations and prospects.

The incorporation of nuclear quantum effects and non-Born-Oppenheimer behavior into quantum chemistry calculations and molecular dynamics simulations is a longstanding challenge. The nuclear-electronic orbital (NEO) approach treats specified nuclei, typically protons, quantum mechanically on the same level as the electrons with wave function and density functional theory methods. This approach inherently includes nuclear delocalization and zero-point energy in molecular energy calculations, geometry optimizations, reaction paths, and dynamics. It can also provide accurate descriptions of excited electronic, vibrational, and vibronic states as well as nuclear tunneling and nonadiabatic dynamics. Nonequilibrium nuclear-electronic dynamics simulations beyond the Born-Oppenheimer approximation can be used to investigate a wide range of excited state processes. This Perspective provides an overview of the foundational NEO methods and enumerates the prospects for using these methods as building blocks for future developments. The conceptual simplicity and computational efficiency of the NEO approach will enhance its accessibility and applicability to diverse chemical and biological systems.

Bioconcentration Factor of Polychlorinated Biphenyls and Its Correlation with UV- and IR-Spectroscopic data: A DFT based Study

Polychlorinated biphenyls (PCBs) are important class of persist organic pollutants that were used as a component of paints especially in printings, as plastificator of plastics and insulating materials in transformers and capacitors, heat transfer fluids, additives in hydraulic fluids in vacuum and turbine pumps. There is always a need to establish reliable procedures for predicting the bioconcentration potential of chemicals from the knowledge of their molecular structure, or from readily measurable properties of the substance. Hence, correlation and prediction of bio-concentration factors (BCFs) based on λmax and vibration frequencies of various bonds viz υ(C-H) and υ(C=C) of biphenyl and its fifty-seven derivatives have been made. For the study, the molecular modeling and geometry optimization of the PCBs have been performed on workspace program of CAChe Pro 5.04 software of Fujitsu using DFT method. UV-visible spectra for each compound were created by electron transition between molecular orbitals as electromagnetic radiation in the visible and ultraviolet (UV-visible) region is absorbed by the molecule. The energies of excited electronic states were computed quantum mechanically. IR spectra of transitions for each compound were created by coordinated motions of the atoms as electromagnetic radiation in the infrared region is absorbed by the molecule. The force necessary to distort the molecule was computed quantum mechanically from its equilibrium geometry and thus frequency of vibrational transitions was predicted. Project Leader Program associated with CAChe has been used for multiple linear regression (MLR) analysis using above spectroscopic data as independent variables and BCFs of PCBs as dependent variables. The reliability of correlation and predicting ability of the MLR equations (models) are judged by R2, R2adj, se, q2L10O and F values. This study reflected clearly that UV and IR spectroscopic data can be used to predict BCFs of a large number of related compounds within limited time without any difficulty.