LANL2DZ Basis Set Research Articles

Calculation and analysis of interaction between characteristic functional group of persimmon tannin and metal ions

Persimmon tannin has excellent adsorption efficiency of heavy metal ions, and epigallocatechin gallate (EGCG) is the key structural monomer of persimmon tannin to play its active role. In order to analyze the nature of the interaction between persimmon tannin and metal ions, in this paper the density functional theory (DFT) is used to calculate and analyze the interactions between EGCG and metal ions (Ag<sup>+</sup>, Hg<sup>2+</sup>, Cu<sup>2+</sup>, Fe<sup>2+</sup>, In<sup>3+</sup>, Al<sup>3+</sup>, Au<sup>3+</sup>), from the respects of EGCG-metal complex configuration, Mayer bond order, natural population analysis, binding energy, and weak interaction. In this paper, the B3LYP combined with DFT-D3 dispersion correction method is mainly used. For metal atoms, the Lanl2dz basis set is adopted. For H, C and O atoms, the 6-311G (d, p) basis set is adopted for optimizing the structure, and the more accurate 6-311+G (d, p) basis set is selected for calculating the single point energy. At the same time, the study adds the SMD solvation model with water as the solvent. All calculations are done by using the Gaussian 09 package. The method of reduced density gradient function is used to study the weak interactions between EGCG and metal ions. The results of research show that EGCG-Fe<sup>2+</sup> complex is adsorbed mainly by chelating bond. However, the EGCG adsorbs mainly Ag<sup>+</sup>, Hg<sup>2+</sup> ions through electrostatic attraction. The configurations of the complexes show that In<sup>3+</sup>, Al<sup>3+</sup> and Au<sup>3+</sup> ions with EGCG form unique “luminal structure” metal complexes, so there is not only electrostatic attraction, but also aromatic ring stacking between these three metal ions and D ring 4<i>"</i>O, 5<i>"</i>O. The calculated Mayer bond order indicates that the bond order of the composite bond is formed by Fe<sup>2+</sup> ion and the EGCG is the largest in the seven metal complexes, and the bond order is formed by In<sup>3+</sup> ion, and EGCG is smallest. The compound of Cu<sup>2+</sup> ion and EGCG have chelation, electrostatic attraction and aromatic ring stacking. By observing the binding energy, it can be found that the more charges the metal ions have, the easier the charge transfer will be and the stronger the electrostatic attraction of EGCG may be. These results will provide enlightenment for further studying the mechanism of persimmon tannin's adsorption of metal ions.

Understanding the regioselectivity of the copper(I)- and ruthenium(II)- catalyzed [3 + 2] cycloadditions of azido derivative of ribose with terminal alkyne: a theoretical study

In the present work, the uncatalyzed, the copper(I)-catalyzed and the ruthenium(II)-catalyzed [3 + 2] cycloadditions (32CA) of azido derivative of ribose with terminal alkyne leading to 1,4- and/or 1,5- 1,2,3-triazole regioisomers have been studied at the B3LYP level of theory in combination with the LanL2DZ basis set for Cu, Ru and Cl atoms and the standard 6-31G(d) basis set for other atoms. The obtained results reveal that the uncatalyzed reaction requires high and similar activation energies, namely 18.29 and 18.80 kcal/mol for the 1,4 and 1,5 regioisomeric pathways, respectively, indicating a very limited regioselectivity in agreement with the experimental outcomes. Interestingly, for the copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC), investigated using the Fokin stepwise mechanism involving two copper atoms, the 1,4 regioisomeric reaction path found to be kinetically more favored than the 1,5 regioisomeric reaction path by 9.13 kcal/mol. By contrast, for the ruthenium(II)-catalyzed azide–alkyne cycloaddition (RuAAC), investigated using the Fokin mechanism using the pentamethylcyclopentadienyl ruthenium chloride [Cp * RuCl] complex, the 1,5 regioisomeric reaction path is more favored than the 1,4 regioisomeric reaction path by 3.48 kcal/mol. The present work puts in evidence the determinant role of Cu/Ru catalysts in the regioselectivity of this click reaction.

Non-covalent Interactions Directed Rearrangement of Lactones to Pyrones: A Computational Study on the Mechanistic Insights of Solvent Assisted Gold(I) Catalyzed Reactions

The mechanism of gold(I) catalyzed cycloisomerization of lactones to pyrones was analyzed by performing DFT study using B3LYP method with LanL2DZ basis set for Au and 6-31g(d) basis set for all other atoms. The potential energy surface of the reaction was scanned to know the preferred path for the formation of products under gas phase. The effects of solvent using acetonitrile, dichloromethane and toluene are explored as these solvents are reported to play a crucial role in the final product formation. The crossover between the oxophilic and alkynophilic reaction complexes, R-O and R-C, is found to be the major driving force which directs the product formation. While the larger energy gap between R-O and R-C leads to pyrone formation, the smaller difference and in turn the rapid crossover between R-O and R-C leads to the formation of decarboxylation adduct. Counterion plays a major role throughout the reaction. The atoms in molecules analysis on R-C using implicit as well as explicit solvent gave reason for the observed experimental trends and suggest that the prevailed non-covalent interactions play a substantial role in the product formation.

Design, structural investigations and antimicrobial activity of pyrazole nucleating copper and zinc complexes

The present study accounts for the construction of two novel complexes by the interaction of pyrazole nucleating ligand with Cu(II) (1) and Zn(II) (2) ions in 1:1 equivalent ratio, and their structural investigation by elemental analyses, FT-IR, NMR and thermal studies. Complex 1, additionally characterized by single crystal X-ray crystallography, reveals the coordination of the pyrazole nucleating ligand to the metal ions by the imine nitrogen, carbonyl oxygen and phenolic oxygen of the ligand and chloride ion. Furthermore, the coordination environment of the central atom adopts slightly distorted square-planar geometry with sum of interbond angles equal to 701.49°. The analysis of CN bond lengths shows that the double bond is localised within imine moiety and respective bonds shows considerable degree of delocalisation within pyrazole ring. The mixed basis set 6-311G(d) and LANL2DZ with B3LYP functional is applied for DFT calculation to determine the bonding insights into the structure of the complex. Natural Population Analysis (NPA) is also carried out to define the nature of the charge on copper atom in complex 1. In addition, Hirshfeld surface analysis is also carried out to know the various intermolecular interactions. The ligand and its complexes were evaluated against Pseudomonas aeruginosa, Escherichia coli, Shigella sonnei, Bacillus subtilis, Aspergillus niger, Aspergillus flavus, Fusarium oxysporum, Penicillium notatum microbial species, and showed significant effects on the tested microbes.

Saturable absorption behavior of (5,10,15,20-tetraphenylporphyrinato)-silver crystal thin film at wavelength 532 nm

A single crystal of (5,10,15,20-tetraphenylporphyrinato)-silver was obtained and its structure reported. Using direct growth on quartz substrates method, a crystal thin film was obtained and the film’s morphology was investigated by atomic force microscopy. The nonlinear absorption properties of the film were studied using open aperture [Formula: see text]-scan technique by picosecond laser pulses at different fluence at wavelength 532 nm, nonlinear saturable absorption behavior was observed. Time-dependent unrestricted Hartree-Fock with the basis set LanL2DZ was used in computing the linear and non-linear optical properties of (5,10,15,20-tetraphenylporphyrinato)-silver.

Comparative structural, spectroscopic and nonlinear optical analysis of a Schiff base compound with experimental and theoretical methods (HF, B3LYP and WB97X-D)

A novel Schiff base compound (E)-N-((2-iodophenyl)-1-(5-nitrothiophen-2-yl)methanimine has been synthesized. The structural characterization of Schiff base compound are confirmed by single crystal X-ray, FT-IR, and UV–vis techniques. The theoretical calculations were obtained by aid of the HF, DFT/B3LYP and WB97X-D methods with the LANL2DZ basis set. The electronic properties and vibrational frequencies in the ground state were investigated same levels of theory. The UV–vis experimental results are compared to the calculated TD-DFT and TDHF results. The NLO properties have been predicted using same calculations and compared with urea molecule. Results indicate that compound is a good candidate as NLO material.

An insight into non-covalent interactions in the tetraphenylarsonium dithiophosphates: Synthesis, DFT and Hirshfeld surface analysis

Three tetraphenylarsonium dithiophosphate salts [Ph4As]+[S2P(OAr)2]−, where Ar = 2,4-(CH3)2C6H3 (1), 3,5-(CH3)2C6H3 (2), {4-(CH3)3C}C6H4 (3), were crystallized in the monoclinic space group P21 (1), triclinic space group P¯1 (2) and monoclinic space group P21/c (3), respectively. These salts are stabilized by various non-covalent interactions resulting in the extension of their molecular structure along different axis. The cationic and anionic species are interconnected by various C—H•••X, C—H•••π (X = O, S) interactions leading the molecules as one-dimensional and two-dimensional supramolecular structures. A thorough Hirshfeld surface analysis elegantly quantifies the various non-covalent interactions present within the molecules. This analysis reveals that the main contributions in all the three salts are because of H…H and C…H/H…C interactions that represent 82.1%, 82.9% and 84.1% of the total contribution to the Hirshfeld surface for 1, 2 and 3, respectively. Further, the coordinates were optimized by DFT calculations with B3LYP hybrid functional along with LANL2DZ basis set. Experimental values of bond lengths and bond angles are in good agreement with the optimized structural parameters. HOMO-LUMO of the molecules were calculated using corresponding methods with the same basis set. Other computational data pertaining to chemical reactivity have indicated potential sites for nucleophilic and eletrophilic attack in the molecules.

Synthesis, crystal structures and theoretical studies of Zinc(II) coordination compounds with 4-trifluoromethylphenyl)imino-methyl]pyridine bidentate Schiff base ligand

[Zn(dip)(Br)2] (1) and [Zn2(dip)2Cl4] (2) zinc(II) coordination compounds were synthesized using 4-trifluoromethylphenyl)imino-methyl]pyridine (dip) bidentate Schiff base ligand and ZnBr2 and ZnCl2 salts. In structure 1, zinc(II) ion exhibits a tetrahedral arrangement while adopting a ZnN2Cl3 trigonal bipyramidal geometry in structure 2. Moreover, in structures 1 and 2, the neutral molecules form a 1D chain structure through the C-H•••F hydrogen bonds. Complex 1 is a monomeric structure while complex 2 has a dimeric structure. Coordination compounds 1 and 2 have been characterized by infrared spectroscopy, elemental analysis and single crystal X-ray diffraction. Density Functional Theory (DFT) calculations at the B3LYP level of theory have been carried out to investigate three types of reactions between ZnCl2 and ZnBr2 metal salts and ligand L in both gas and solution phases. The optimized geometrical parameters of the complexes were evaluated using SDD, CEP-121G, and LANL2DZ basis sets. The gas phase calculations show that the binuclear Zn2L2X4 (Zn2L2Cl4 and Zn2L2Br4) complexes are more stable than mononuclear ZnLX2 (ZnLCl2 and ZnLBr2) and ZnL22+ complexes. However, the solution studies indicate that the formation of Zn2L2Cl4 and ZnLBr2 complexes is energetically more favorable compared with the other complexes.

Theoretical studies on photocatalytic application of GO-ZnO nanocomposite for the reduction of methylene blue dye

Abstract The non-linear optical properties, natural bond orbital and density of states (DOS) of GO-ZnO were calculated using density functional theory (DFT) calculations with B3LYP method at 6-31G (d,p) and LanL2DZ basis sets to examine the binding site of a methylene blue (MB) dye systematically. The result of NBO analysis revealed the effective charge transfer and also explained the mechanism and efficiency of the photocatalytic activity of GO-ZnO. Density of states supported the strong interaction of MB with the GO-ZnO leading to the degradation of the MB dye. The higher electrical conductivity is studied using DOS spectral analysis. The attained theoretical results depict the existence of n → σ*, n → n* and σ → σ* interactions, improved charge transfer, reduced band gap which establish the use of GO-ZnO in the visible light photocatalytic performance.

Synthesis, in vitro anticancer activities, and quantum chemical investigations on 1,3-bis-(2-methyl-2-propenyl)benzimidazolium chloride and its Ag(I) complex

1,3- Bis-(2-methyl-2-propenyl)benzimidazolium chloride and its Ag(I) complex are synthesized and the structures are elucidated using spectroscopies techniques. The molecular and crystal structures of the benzimidazolium salt are confirmed by X-ray crystallography. The molecular geometries of the benzimidazolium and its Ag(I) salt are analyzed using the B3LYP functional with the 6–311+G(d,p)/LANL2DZ basis set. The observed Fourier transform infrared and nuclear magnetic resonance isotropic shifts are compared with the calculated values. Besides, the quantum chemical identifiers, significant intramolecular interactions, and molecular electrostatic potential plots are used to show the tendency/site of the chemical reactivity behavior. The three-dimensional Hirshfeld surfaces and the associated two-dimensional fingerprint plots are applied to obtain an insight into the behavior of the interactions in the crystal. Both compounds are tested for their in vitro anticancer activities against DU-145 and MCF-7 cancer cells and L-929 non-cancer cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

Stercobilin and Urobilin in Aqueous Media: Existence of Specific H-Aggregates and Nonspecific Higher Aggregates at Different Concentrations.

Fecal matter is considered to be one of the primary sources of water pollution. Understanding the aggregation behavior of the fecal pigments (FPs) could play a critical role in their detection and analysis. This work shows that in aqueous media, the fluorescence of FPs indicates the presence of multiple emitting species, which have been assigned to monomers, lower-order H-aggregates (dimers), and higher-order H-aggregates. Steady-state absorbance, fluorescence and time-resolved fluorescence decay studies conclude that the emission of FPs in aqueous medium indicates H-type of aggregation, even up to nanomolar and sub-nanomolar concentrations. Four sets of independent experiments involving the variation of (i) concentration of FPs, (ii) temperature, (iii) pH, and (iv) ethanol/water composition as solvent media suggest the presence of monomer (540 nm), dimer (516 nm), and higher-order aggregates (500 nm) of FPs in aqueous solutions. The dimeric FP species appear to be present in the entire concentration range of 1 pM to 1 μM. Fluorescence lifetimes of H-aggregates are relatively longer as compared to the corresponding monomers. Hydrogen bonding appears to play an important role in forming H-aggregates in the aqueous phase of FPs as observed in the IR spectra of the FPs in dichloromethane. Density functional theory (DFT) calculations using the B3LYP functional and the LANL2DZ basis set show the contributions of π-π stacking and hydrogen-bonding interactions toward the formation of H-aggregated dimer of FPs in aqueous media.

Quasi-Static Two-Dimensional Infrared Spectra of the Carboxyhemoglobin Subsystem under Electric Fields: A Theoretical Study.

There is no doubt that electric fields of a specific frequency and intensity could excite certain vibrational modes of a macromolecule, which alters its mode coupling and conformation. Motivated by recent experiments and theories, we study the mode coupling between the Fe-CO mode and CO-stretch mode and vibration energy transfer among the active site and proteins in carboxyhemoglobin (HbCO) under different electric fields using the quasi-static two-dimensional infrared spectra. This study uses iron-porphyrin-imidazole-CO and two distal histidines in HbCO as the subsystem. The potential energy and dipole moment surfaces of the subsystem are calculated using an all-electron ab initio (B3LYP-D3(BJ)) method with the basis set Lanl2dz for the Fe atom and 6-31G(d,p) for C, H, O, and N atoms. Although the subsystem is reduced dimensionally, the anharmonic frequency and anharmonicity of the CO-stretch mode show excellent agreement with experimental values. We use the revealing noncovalent interaction method to confirm the hydrogen bond between the Hε atom of the His63 and the CO molecule. Our study confirms that the mode coupling between the Fe-CO mode and CO-stretch mode does not exist when the subsystem is free of electric field perturbation, which is coupled when the electric field is -0.5142 V/nm. In addition, with the increases of distance between the active site and the His92, there is no vibrational energy transfer between them when the electric field is 1.028 V/nm. We believe that our work could provide new ideas for increasing the dissociation efficiency of the Fe-CO bond and theoretical references for experimental research.

Crystal thin film of bis (imidazole) silver(I) nitrate for all optical switching application

The single crystal of a silver complex bis (imidazole) silver(I) nitrate (Ag(C3H4N2)2(NO3), BISN) has been obtained and characterized by X‐ray single‐crystal diffraction. Its crystal thin film was prepared using direct growth on quartz substrates. The surface morphology of the thin film was studied by atomic force microscopy (AFM). The nonlinear optical (NLO) properties of the thin film were investigated by using closed‐aperture Z‐scan technique with 20 picosecond (ps) pulses at wavelength 532 nm. Using time‐dependent density‐functional theory (TDDFT) with the basis set LanL2DZ, its linear and NLO properties were calculated.

The Interaction of Adenine with Zn12O12 Cluster from Density Functional Theory

Geometries associated energy gap and electronic properties of adenine, DNA base interaction on the ZnO model cluster have been investigated by using density functional theory with the B3LYP exchange-correlation potential and effective core potential (ECP) LanL2DZ basis sets. The most stable interaction characteristics were analysed with respect to the binding energy, frontier orbital, elemental positions. Natural population analysis charge is also examined to understand the associated charge transfer in structures of cluster and complex. In the Zn-N bonding, combination coefficient from atom orbitals of nitrogen is much higher than that of zinc. The corresponding weight for this coefficient is 94.80%. The results of this study can serve as an orientation for the design of composite material in biomedical nanotechnology.

Effect of Copper on 1,1-Diamino-2,2-dinitroethene - A DFT Treatment

Interaction of 1,1-diamino-2,2-dinitroethene which is a well known explosive called FOX-7 and copper atom is investigated computationally in the form of 1:1 composite, at the levels of UB3LYP/6-31++G(d,p) and UB3LYP/LANL2DZ within the restrictions of density functional theory. Some geometrical, spectral and quantum chemical data have been obtained and discussed. The both levels of computational approach yield geometries in accord with each other but LANL2DZ basis set produced unreasonable charges for the atoms of the composite. However, both of the methods indicate that copper atom donates some electron population to the organic component meantime the nitro groups change their conformation by twisting about the C-NO2 bonds. Thus, the push-pull character of the system varies which should affect some of the explosive properties, beside the others.

Spectroscopic studies, density functional theory calculations, non-linear optical properties, biological activity of 1-hydroxy-4-((4-(N-(pyrimidin-2-yl)sulfamoyl)phenyl)diazenyl)-2-naphthoic acid and its chelates with Nickel (II), Copper (II), Zinc (II) and Palladium (II) metal ions

Novel Nickel (II), Copper (II), Zinc (II) and Palladium (II) chelates with 1‑hydroxy-4-((4-(N-(pyrimidin-2-yl)sulfamoyl)phenyl)diazenyl)-2-naphthoic acid (H3L) have been produced and clarified using several physicochemical techniques. Quantum mechanical calculations of energies, geometries were achieved by using the density functional theory with Becke's three parameter exchange functional, the Lee_Yang_Parr correlation functional (B3LYP/GEN) combined with 6.311 G (d,p) and LANL2DZ basis sets. The analyses of Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) have been used to justify the charge transfer within the ligand and its chelates. The considered small energy gap between Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energies expressions that the charge transfer occurs within the ligand and its chelates. The results show that the azo dye ligand exists in two tautomeric structures, the first structure (H3L), the sulphonamide (SO2NH), while the second one, the sulphonamide group in enolic form (H2L-OH). The H2L-OH tautomer has energy of 12.93 kcal/mol higher than that of H3L. The structure of H3L was found to be the most stable and used as the ligand in this study. The bond lengths of Ni(II) ion with the donating sites of the ligand in Ni-(H2L)2 chelate suggest a distorted octahedral geometry, Cu2-(L) chelate, suggests a highly distorted tetrahedral geometry, Zn-(HL) chelate displays a distorted octahedral geometry, Pd-(H2L) chelate approves a distorted square planar geometry around its own central metal ion. Geometrical parameters, molecular electrostatic potential maps and total electron densities analyses of the ligand and its chelates have been carried out. Molecular stability, hyper conjugative interactions, intramolecular charge transfer and bond strength have been examined by applying of natural bond orbital (NBO) analysis. Total static dipole moment, mean polarizability, anisotropy of the polarizability, mean first-order hyperpolarizability have been also achieved. From the molecular hyperpolarizability (˂β˃), The computed (˂β˃) values show that for the ligand (H3L) and its Ni-(H2L)2, Cu2-(L), Zn-(HL) and Pd-(H2L) are ~23, ~70, ~44, ~132 and ~38 times greater than that of Urea, indicating all the studied ligand and its chelates reveal significant polarizability and first-order hyperpolarizability and are predicted to be successful for Non-Linear Optical (NLO) materials. The analyses of the chelates indicate that the Zn(II) and Pd(II) form 1:1, Ni(II) form 1:2 while Cu(II) ion form 2:1 (M:L) and non-electrolytic behavior of chelates indicate the absence of counter ion. Ni-(H2L)2 complex had zero antibacterial activity against E. coli while its activity is higher than the azo dye against Staphylococcus aureus. Pd-H2L complex had almost the same activity as the azo dye against both types of bacteria. The higher activity of Zn-HL and Cu2-L complexes can be explained by their chelation.

Synthesis, characterization, molecular structure and computational study of tetrahedral pentamethylcyclopentadienyl iridacycle complexes with α,β-conjugated Schiff base ligands

Due to the excellent catalytic activities and phosphorescent properties that iridium complexes display, iridium chemistry has been of great interest for scientific investigation over the past 30 years. Iridium metallacycle analogues (also known as an iridacycles) bearing phenylpyridine (ppy) ligands have been well reported on, whilst complexes with R-phenyl-(3-R-phenylallylidene)amine, which is an α,β-conjugated Schiff base ligand, have not had the same attention, despite the fact that both ligands share a similar coordination mode. In this research, four pentamethylcyclopentadienyl iridacycle complexes, Ir1a-Ir1d, with different α,β-conjugated Schiff base ligands were synthesized from a di-μ-chloro-dichloro-bis-(η5-pentamethylcyclopentadienyl)diiridium(III) precursor. The iridacycle complexes were characterized using spectroscopic techniques and the molecular structures of Ir1ab-Ir1d were determined using X-ray crystallography. The X-ray results revealed that the iridacycle complexes have a tetrahedral geometry, the iridium centre being coordinated through the NCCαCβ moiety of the α,β-conjugated Schiff base ligand. Computational calculations with the B3LYP method and with LanL2DZ basis sets indicated that the HOMO-LUMO energy gaps Ir1b-Ir1d were in the range 3.31–3.36 eV. The OMe substituent at the C terminal has a greater impact on the HOMO energy level than the one at the N terminal.

L–Alanine adsorbed aluminum doped ZnO structures for nanocomposites with tailored photovoltaic properties: a DFT study

The l-Alanine adsorbed Al-doped Zn8O8 (l-A-AlZn7O8) with an amine site (P1) and carboxyl site (P2) were investigated through density functional theory (DFT) calculations using B3LYP method with 6-31G (d,p) and LanL2DZ basis sets to improve the electrochemical properties. The geometrical parameters, optical properties, lowest harmonic frequency, polarizability, dipole moment, Mulliken atomic charges, adsorption energy, HOMO–LUMO gap, molecular electrostatic potential, global reactivity descriptors, Fukui functions and density of states (DOS) were examined in detail. The adsorption energies have been calculated for different possible configurations of the l-A-Al(ZnO)n. The excited state geometry optimization and UV–Vis spectral analysis were carried out with the time-dependent DFT. The net charge transfer and local charges of l-A-AlZn7O8 are studied by natural bond orbital analysis. The DOS plot reveals that the remarkable orbital hybridization and strong interaction between l-Alanine and Al-doped ZnO. The electronic properties of l-A-AlZn7O8 undertake an important modification that indicates the noteworthy changes in its electrical conductivity. The P1 site characteristics were interesting for dye-sensitized solar cells as it offers significant adsorption energy, elevated net charge transferring values, and smaller bond distances in the P1 site of l-A-AlZn7O8.

Cobalt and zinc tetraphenylporphyrins thin films for all optical switching application

Abstract Cobalt and zinc tetraphenylporphyrins have been obtained and characterized by X-ray single crystal diffraction. Their crystal thin films were prepared using direct growth on quartz substrates. The surface morphology of the thin films were studied by atomic force microscopy. The nonlinear optical refraction properties of the thin films were investigated by using closed aperture Z-scan technique with 20 ps (ps) pulses at wavelength 1064 nm. Time-dependent unrestricted Hartree-Fock (TDUHF) with the basis set LanL2DZ were used in computing the linear and non-linear optical properties.

Synthesis, crystal structure, IR, Raman-spectroscopy and DFT computation of monostrontium phosphate monohydrate, Sr(H2PO4)2·H2O

The compound Sr(H2PO4)2·H2O has been synthesized and studied by single crystal X-ray diffraction analysis, infrared and Raman vibrational spectroscopy and density functional theory calculations. This compound crystallizes in the triclinic centrosymmetric space group P-1(Z = 2) with a = 5.7641(4) Å, b = 6.4549(4) Å, c = 12.0746(9) Å, α = 93.386(2)°, β = 95.730(2)° and γ = 114.114(2)°. The three-dimensional structure contains Sr(H2PO4)+ chains, which form corrugated layers. Between these layers are placed layers of (H2PO4)- ions and water molecules. The bands observed in the infrared and Raman spectra of Sr(H2PO4)2·H2O are assigned based on the results obtained in the literature and upon theoretical group analyses made in the factor group Ci. The optimal molecular geometry, harmonic vibrational frequencies, infrared intensities and Raman scattering activities were calculated by using density function theory (DFT/B3LYP) methods with the LanL2DZ basis set. The HOMO-LUMO properties and geometries of this compound have been determined and discussed. The computational structural parameters are generally in agreement with the experimental investigations. The theoretical infrared and Raman spectra for the title compound have been constructed.