Insights into Proton Dynamics in a Photofunctional Salt-Cocrystal Continuum: Single-Crystal X-ray,Neutron Diffraction,and Hirshfeld Atom Refinement

X-ray diffraction, neutron diffraction, and theoretical calculations were used to investigate the relationship between the optical properties and degree of protonation in acid-base complexes. We prepared five acid-base complexes by using a pyridine-modified pyrrolopyrrole derivative and salicylic acid. Two of the prepared acid-base complexes were polymorphs of guest-free crystals with green emission; the other three were guest-inclusion crystals with yellow emission containing CH₂Cl₂, CH₂Br₂, or C₂H₄Cl₂. The presence or absence of guests caused the emission to change color, altering the hydrogen bond strength between the acid-base complexes. Accurate N⋅⋅⋅H distances between the pyridyl moiety and the carboxy group over the temperature range 123 to 273 K were 1.40 Å for the guest-free crystals and 1.25 Å for the guest-inclusion crystals. Our findings contribute to a better understanding of the complex relationship between photofunction and proton dynamics in acid-base complexes.     

基于LabVIEW的氢原子及类氢原子波函数等密度线的可视化程序开发

编程实现了基于LabVIEW的氢原子及类氢原子不同能级波函数的等密度线可视化程序,该程序能自动完成波函数ψ2nlmr,θ,φ在不同角度(θ,φ)时随r变化的曲线及任意截面等密度线图的绘制。应用表明:该程序对氢原子及类氢原子波函数立体图形全局有一个非常直观的描述,能够直观地反映原子、分子的电子结构,并给出立体图不能反映的细节,有助于对化学反应过程、成键本质的理解。同时基于LabVIEW开发的可视化程序具有编程直观高效、界面友好、功能易扩展等优点。     

含2,5-二巯基-1,3,4-噻二唑的过渡金属配合物的合成及性质研究

含２，５－二巯基－１，３，４－噻二唑的过渡金属配合物的合成及性质研究郭胜利殷元骐＊（中国科学院兰州化学物理研究所７３００００）含单巯基的有机物与过渡金属形成的配合物，作为金属硫蛋白的模拟化合物，这方面研究已多有报道［１～３］。含两个及以上巯基的化合物...     

Syntheses,Hirshfeld surface analyses,and luminescence of four new complexes

Four Cd-based complexes with chemical formulae [Cd(L¹)₂(2,2'-Bipy)(H₂O)] (I), [Cd(L²)₂(2,2'-Bipy) · 2H₂O] (II), [Cd(L¹)₂(Phen)(H₂O)] (III), {[Cd(L¹)₂(H₂O)(4,4'-Bipy)] · 3H₂O} (IV) (HL¹ = 3-(4-hydroxyphenyl)propanoic acid, HL² = p-hydroxyphenylacetic acid, Phen = phenantroline), have been synthesized and structurally characterized (CIF file CCDC nos. 1044844 (I), 1044844 (II), 1044844 (III), 1044847 (IV)). Single-crystal X-ray analyses reveal that compounds I and III have mononuclear Cd(II) units linking by three carboxylate groups, complex II shows dinuclear motif, whereas IV exhibits 1D chain constructed by bridging 4,4'-Bipy ligand. The assistant effect of chelating N-donor ligands with 2,2'-Bipy and Phen bind and bridging 4,4'-Bipy, as well as the flexibility of carboxylate, play an important to modulate on the resulting motifs. The detailed analyses of Hirshfeld surface and fingerprint plots provide insight into the nature of non-covalent interactions in the title compounds. Furthermore, the luminescent properties of the all compounds were discussed in detail.     

From Shape Similarity to Shape Complementarity: Toward a Docking Theory

Formal relations between similarity and docking are analyzed, and a general docking theory is proposed for colored mixtures of multivariate distributions. X and Y being two colored mixtures with given marginal distributions, their shape complementarity coefficient is defined as the lower bound of the variance of (X–Y)· (X-Y), taken over the set of joint distributions of X and Y. The docking is performed via minimization of the shape complementarity coefficient for all translations and rotations of the mixtures. The properties of the docking criterion are derived, and are shown to satisfy the practical requirements encountered in molecular shape analysis.     

Atomic charges,dipole moments,and Fukui functions using the Hirshfeld partitioning of the electron density

In the Hirshfeld partitioning of the electron density, the molecular electron density is decomposed in atomic contributions, proportional to the weight of the isolated atom density in the promolecule density, constructed by superimposing the isolated atom electron densities placed on the positions the atoms have in the molecule. A maximal conservation of the information of the isolated atoms in the atoms-in-molecules is thereby secured. Atomic charges, atomic dipole moments, and Fukui functions resulting from the Hirshfeld partitioning of the electron density are computed for a large series of molecules. In a representative set of organic and hypervalent molecules, they are compared with other commonly used population analysis methods. The expected bond polarities are recovered, but the charges are much smaller compared to other methods. Condensed Fukui functions for a large number of molecules, undergoing an electrophilic or a nucleophilic attack, are computed and compared with the HOMO and LUMO densities, integrated over the Hirshfeld atoms in molecules.     

信息论与化学计量学

本文讨论了信息论在发展分析化学计量学中的意义和作用以及信息论在化学计量学中应用的一般规律和关系，总结了信息科学对化学计量学发展的贡献。     

Association and Shape of Molecules Using Free Length Theory

Abstract

Traditionally workers engaged in calculation of the ultrasonic velocity in liquid mixtures using Jacobson's Free Length Theory (FLT) arrive at the conclusion that the predictions of FLT produce large deviations when compared with experimental velocities. Such workers seemed to have ignored the necessity of incorporating two parameters in FLT as originally suggested by Jacobson himself: one, to account for the association, and the other, for the shape of the component molecules in the mixture. By introducing the association factor and deriving explicit expressions for different shapes of the molecules, the present work has demonstrated that FLT might be made to predict ultrasonic velocities in the mixtures better. Also this approach can very well be used to account for molecular associations and shapes.     

Critical analysis and extension of the Hirshfeld atoms in molecules

The computational approach to the Hirshfeld [Theor. Chim. Acta 44, 129 (1977)] atom in a molecule is critically investigated, and several difficulties are highlighted. It is shown that these difficulties are mitigated by an alternative, iterative version, of the Hirshfeld partitioning procedure. The iterative scheme ensures that the Hirshfeld definition represents a mathematically proper information entropy, allows the Hirshfeld approach to be used for charged molecules, eliminates arbitrariness in the choice of the promolecule, and increases the magnitudes of the charges. The resulting "Hirshfeld-I charges" correlate well with electrostatic potential derived atomic charges.     

Generalized Hirshfeld Partitioning with Oriented and Promoted ProatomsSCI北大核心CSCD

In this study, we show how to generalize Hirshfeld partitioning methods to possibly include non-spherical proatom densities. While this generalization is numerically challenging(requiring global optimization of a large number of parameters), it is conceptually appealing because it allows the proatoms to be pre-polarized, or even promoted, to a state that more closely resembles the atom in a molecule. This method is based on first characterizing the convex set of proatom densities associated with the degenerate ground states of isolated atoms and atomic ions. The preferred orientation of the proatoms' densities are then obtained by minimizing the information–theoretic distance between the promolecular and molecular densities. If contributions from excited states(and not just degenerate ground states) are included in the convex set, this method can describe promoted atoms. While the procedure is intractable in general, if one includes only atomic states that have differing electron-numbers and/or spins, the variational principle becomes a simple convex optimization with a single unique solution.     

Tertiary phosphine-appended transition metal ferrocenyl dithiocarbamates: Syntheses,Hirshfeld surface,and electrochemical analyses

Five new heteroleptic complexes of Cu(I), Ag(I), and Ni(II) having formulae [Cu₃(dtc)₂(dppf)₂]PF₆ ( Cu-I ), [Cu₃(dtc)₂(dppe)₂]PF₆ ( Cu-II ), [Cu(PPh₃)₂(dtc)] ( Cu-III ), [Ag₃(dtc)₂(PPh₃)₂]NO₃ ( Ag-I ), and [Ni(dtc)(dppf)]PF₆ ( Ni-I ) (dtc = N-ethanol-N-methylferrocenyl-dithiocarbamate; dppf = 1,1′-bis(diphenylphosphino)ferrocene; dppe = 1,1′-bis(diphenylphosphino)ethane; PPh₃ = tripheylphosphine) have been synthesized and characterized using elemental analysis, Fourier-transform infrared, multinuclear nuclear magnetic resonance, UV–Vis spectroscopy, and single-crystal X-ray diffraction. The single-crystal X-ray diffraction studies indicate that Ag-I forms a rare trinuclear cluster in which the geometry around the two silver centers Ag1 and Ag3 is distorted tetrahedral, whereas the third silver center Ag2 shows a distorted trigonal planar geometry. The Ni-I complex has a distorted square-planar geometry around the Ni center. In addition, a side product [Ag₂{S₂(dppf)₂}] ( Ag-II ) was obtained during an attempt to synthesize [Ag(dppf)(dtc)], where the two Ag centers are bridged by two sulfido centers and coordinated with two phosphorus centers of the dppf ligand to give rise to a distorted tetrahedral geometry. The solid-state structures of Ag-I , Ni-I , and Ag-II are stabilized by a variety of weak interactions. The nature of these interactions has been addressed with the help of Hirshfeld surface analyses. In addition, the weak argentophilic interaction in Ag-I and Ag-II have been studied using quantum theory of atoms in molecules and natural bond orbital calculations. The electrochemical properties of the complexes have been investigated using cyclic voltammetry, where Cu-I and Cu-II exhibited two quasi-reversible waves, whereas Cu-III , Ag-I , Ag-II , and Ni-I exhibited only one quasi-reversible peak.     

Molecular Adducts of Isoniazid: Crystal Structure,Electronic Properties,and Hirshfeld Surface Analysis

Three molecular adducts of the antituberculosis drug isoniazid (INH) are synthesized with γ-resorcylic acid (γRA), phloroglucinol (PG), and gallic acid (GA). The new solid phases are preliminarily characterized by the thermal analysis (DSC/TGA) and powder X-ray diffraction. The formation of new solid phases is confirmed by single crystal X-ray diffraction, infrared (FT-IR) and Raman spectroscopy. All three new solid crystalline forms are stabilized by various hydrogen bonding interactions such as N⁺···H–O^–, N···H–O, O···H–O, and π–π stacking. The FT-IR analysis puts forward that the solid form of INH1 is a salt whereas the INH2 and INH3 molecular complexes are cocrystals. We have also investigated the density of states (DOS), band structure, and atomic orbit projected density of state (PDOS) of title compounds by adopting the density functional theory (DFT) technique in the local density approximation (LDA). The electronic structure calculations show that energy states are delocalized in the k-space due the hydrogen and covalent bonds in the crystals. The frontier molecular orbital (FMO) analysis reveals that charge transfer takes place within the compounds. The Hirshfeld analysis shows that H–H and N?H–O hydrogen bonding interactions are dominant in all three molecular adducts of INH.     

Dipole and quadrupole moment functions of the hydrogen halides HF, HCl, HBr, and HI: a Hirshfeld interpretation

The dipole and quadrupole moment functions of the hydrogen halides are calculated using a large polarized basis and correlated wavefunctions and compared to experiment and previous calculations. These functions are analyzed in terms of local moments constructed using the Hirshfeld method. The dipole moment is the sum of the functions q(H)R+mu(H) and mu(X) with q(H) being the charge on the hydrogen atom, R the internuclear separation, mu(H) and mu(X) the atomic dipoles on the hydrogen and halogen atoms. We find that q(H)R+mu(H) is always positive and has a maximum at bond lengths larger than the equilibrium. In HF, mu(F) is slightly positive at the maximum in q(H)R+mu(H) and has little effect on the resultant maximum in the dipole moment function (DMF). mu(Cl), mu(Br), and mu(I), on the other hand, are increasingly more negative at the maximum of q(H)R+mu(H) and have a profound effect on the width of the maximum of the resulting DMF, successively broadening it and completely eliminating it at HI. The quadrupole moment function (QMF) (with the halogen as origin) is given by Theta(HX)=Theta(HX) (proto)+deltaTheta(X)+deltaTheta(H)+2mu(H)R+q(H)R(2), where Theta(HX) (proto) is the quadrupole moment of the separated atoms (the halogen in this instance) and deltaTheta(X)+deltaTheta(H) the change in the in situ quadrupole moments of the halogen and hydrogen atoms. The maximum in the QMF and its slope at equilibrium are determined essentially by 2mu(H)R+q(H)R(2), which is known once the DMF is known. deltaTheta(X)+deltaTheta(H) is always negative while Theta(HX) (proto) is positive, so one can approximate the molecular quadrupole moment to within 10% as Theta(HX)>Theta(HX) (proto)+2mu(H)R+q(H)R(2).     

A test of the Hirshfeld definition of atomic charges and moments

Summary The Hirshfeld population analysis scheme which carves the molecular density into atomic density contributions is tested. This method does not require a reference to basis sets or their respective locations, but is based on a different physical and mathematical footing. The advantage of this method is that, when the molecular deformation density converges to the true solution, the computed net charges will necessarily converge. This method also allows a straightforward definition for local moments. About 36 molecules have been used to compute the conventional Mulliken and Löwdin population analyses with STO3G, 6311G** and Dunning-Hay split valence basis sets. These results have been compared to the estimates provided by the Hirshfeld model. The charges found in the Hirshfeld method are smaller than those from the other methods.     

Structural,Hirshfeld surface and spectroscopic studies of the noncentrosymmetric 1-ethylpiperazinediium pentachloroantimonate (III) monohydrate

1-Ethylpiperazinediium pentachloroantimonate (III) monohydrate, C₆H₁₆N₂SbCl₅·H₂O, has been synthesized by the reaction of antimony trioxide (Sb₂O₃) and 1-ethylpiperazine in an aqueous solution of hydrochloric acid. The structure crystallizes in orthorhombic system, in the non-centrosymmetric space group Pca2₁ and consists of isolated [C₆H₁₆N₂]²⁺ cations, square pyramidal [SbCl₅]²⁻ anions and lattice water molecules. OH⋯Cl hydrogen bonds link the [SbCl₅]²⁻ anions and water molecules to form double chains stretching along the [101] direction. The chains in turn are linked to the organic cations via NH⋯Cl, CH⋯Cl, CH⋯O and NH⋯O hydrogen bonds to form a three-dimensional network. This structure presents an example of a general square pyramidal complex ion containing a stereo-chemically active lone pair of electrons. Solid state ¹³C and ¹⁵N CP-MAS NMR spectra are in agreement with the X-ray structure, and vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed the attribution of the NMR peaks and IR absorption bands. The interactions variability of the two independent cations and ten chloride atoms is analyzed via Hirshfeld surface analysis.     

叔丁氧基自由基引发氢迁移过程的理论研究

采用多种密度泛函理论方法(如CAM-B3LYP, M062x和wB97x方法), 并辅以极化连续介质模型对叔丁氧基自由基(^tBuO·)与一系列胺类、 烷烃、 醇类和醚类反应物之间氢迁移反应的反应机理进行研究. 计算结果表明, 这类氢迁移反应主要受熵的控制. 通过对液相平动熵和气相平动熵得到的活化自由能数据进行对比, 可以看出, 使用气相平动熵得出的活化自由能明显偏高于实验测量值, 而以液相平动熵计算的反应活化自由能垒与实际结果相近, 3种方法对胺类和烷烃类反应物体系得出的结果更可靠, 对醇类和醚类反应物体系自由能垒则略低.     

Synthesis,crystal structures,fluorescence, electrochemiluminescent properties,and Hirshfeld surface analysis of four Cu/Mn Schiff-basecomplexes

Four new complexes [Cu(L¹)₂]_n ( 1 ), [Mn(L¹)₂]_n ( 2 ), [Cu(L²)₂]_n ( 3 ), [Mn(L²)₂]_n ( 4 , HL¹ = 2-(((4H-1,2,4-triazol-4-yl)imino)methyl)-4,6-dichlorophenol; HL ² = 2-(((4H-1,2,4-triazol-4-yl)imino)methyl)-4,6-dibromophenol) were synthesized by microreaction bottle method. Complexes 1 and 3 and 2 and 4 are isomorphous heterostructures having the same molecular structure. The structures of 1 – 4 were characterized using single X-ray diffraction, Fourier-transform infrared spectroscopy, powder X-ray diffraction, and thermogravimetric analysis, and their potential applications were analyzed by detecting their fluorescence and electrochemical luminescence (ECL). Hirshfeld surface analysis indicates that X···H (X = Br, Cl) interactions play a crucial role in stabilizing the self-assembly process of 1 – 4 , which show highly intense ECL in N,N-dimethylformamide solution and high thermal stability.     

Synthesis,Crystal Structures,Hirshfeld Surfaces,Thermo Characteristics and Solubility of Co-crystal of Buprofezin with Hydrofluoric Acid

A new kind of co-crystal of buprofezin(C(16)H(24)FN3OS) with hydrofluoric acid has been prepared through evaporation technique. It crystallizes in the triclinic space group P1, with a = 9.9733(8), b = 10.3460(9), c = 10.5739(12) ?, a = 68.655(9), b = 73.291(9), g = 66.738(8)o, V = 920.34(17) ?~3, Mr = 325.44, Dc = 1.174 g/cm^3, Z = 2, F(000) = 348, m = 0.190 mm^-1, the final GOOF = 1.042, R = 0.0485 and wR = 0.1167. Single-crystal X-ray diffraction, XRPD, DSC, TGA, Hirshfeld surface analysis, Raman spectroscopy and FT-IR were used to characterize the co-crystal. It has a twodimensional plane structure, and the intermolecular interactions of co-crystal are mainly H–F×××H, H–O×××H and H–O×××H. Thermology study further confirmed that co-crystal has stronger thermal stability and higher melting point than buprofezin, and it has stronger water solubility. The results show that this co-crystal is valuable for the study of residual activity and application effects of buprofezin.