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Showing papers on "Tetrahedral molecular geometry published in 2018"


Journal ArticleDOI
TL;DR: The high photoluminescence quantum yields and fascinating dual-emissive phosphorescence coupled with high thermal stability and solubility suggest a high potential of this novel class of emissive Mn2+ complexes as promising emitters for OLED devices and potential stimuli-responsive materials.
Abstract: Unprecedented organic–inorganic hybrid complexes, [Mn(L)3]MnHal4, containing both four- and hexacoordinated Mn2+ ions were synthesized by reacting MnCl2 or MnBr2 with bis(phosphine oxide) ligands (L) such as dppmO2, dppeO2, and 2,3-bis(diphenylphosphinyl)-1,3-butadiene (dppbO2). In the [Mn(L)3]2+ cation of the complexes, the Mn2+ ion features a [MnO6] octahedral coordination environment (Oh), and the [MnHal4]2− anion adopts a tetrahedral geometry (Td). These “two-in-one” complexes exhibit strong long-lived luminescence (τav = 12–15 ms at 300 K) having interesting thermochromic behavior attributed to the thermal equilibrium between two emission bands. So, in an emission spectrum of the typical complex [Mn(dppbO2)3]MnBr4, the intense “red” (ca. 620 nm) and weak “green” (ca. 520 nm) bands, originating from Mn2+ ions in Oh and Td environments, respectively, are observed. Cooling from 300 to 77 K simultaneously leads to (i) redshift of both bands by ca. 20 nm, (ii) increasing their intensities, and (iii) causing a substantial change of their integral intensity ratio from about 4 : 1 to 2 : 1. As a result, the colour of the emission changes from orange (CIE 0.56, 0.45) at 300 K to deep red (CIE 0.62, 0.39) at 77 K. This behavior was rationalized using steady-state and time-resolved fluorescent spectroscopy at various temperatures. The high photoluminescence quantum yields (up to 61% at 300 K) and fascinating dual-emissive phosphorescence coupled with high thermal stability and solubility suggest a high potential of this novel class of emissive Mn2+ complexes as promising emitters for OLED devices and potential stimuli-responsive materials.

53 citations


Journal ArticleDOI
TL;DR: The influence of conformational rigidity in the precursors on the formation of a [4+4] imine cage with truncated tetrahedral geometry is discussed.
Abstract: The synthesis of shape-persistent organic cage compounds is often based on the usage of multiple dynamic covalent bond formation (such as imines) of readily available precursors. By careful choice of the precursors geometry, the geometry and size of the resulting cage can be accurately designed and indeed a number of different geometries and sizes have been realized to date. Despite of this fact, little is known about the precursors conformational rigidity and steric preorganization of reacting functional groups on the outcome of the reaction. Herein, the influence of conformational rigidity in the precursors on the formation of a [4+4] imine cage with truncated tetrahedral geometry is discussed.

51 citations


Journal ArticleDOI
TL;DR: A new mechanism of luminescent vapochromism is proposed because of the reversible conversion of ligand fields in manganese(II) complexes.
Abstract: The reactions of MnBr2 and ethane-1,2-diylbis(diphenylphosphine oxide) (dppeO2) in dichloromethane-methanol solutions gave colorless crystals with the general chemical formulas [MnBr2(dppeO2)] n (1), [MnBr2(dppeO2)(DMF)] n (1a), [Mn(dppeO2)3][MnBr4] (2), and Mn2Br4(dppeO2)2 (3) depending on the crystallization conditions. Compounds 1 and 1a display one-dimensional chain structures composed of Mn(II) ions linked by bridging dppeO2 to exhibit tetrahedral (1) or trigonal-bipyramidal (1a) coordination geometry, whereas 3 exhibits a cyclic dinuclear structure with two Mn(II) centers bridged by double dppeO2 to adopt tetrahedral geometry. Compound 2 consists of octahedrally coordinated cation [Mn(dppeO2)3]2+ and tetrahedrally arranged anion [MnBr4]2-. While 1 and 3 in crystalline and powder states are highly luminescent with green emission bands centered at ca. 510 nm, 2 shows intense orange luminescence peaking at 594 nm. Upon exposure of 1 to N, N-dimethylformamide vapor, the green emission centered at 510 nm is converted to red luminescence peaking at 630 nm, ascribed to the formation of DMF-coordinated compound 1a with a trigonal-bipyramidal ligand field, as demonstrated by X-ray crystallography. Red-emitting 1a could be reverted to the original green-emitting 1 with a tetrahedral ligand field upon heat at 160 °C, and such a reversible conversion could be perfectly repeated for several cycles. A new mechanism of luminescent vapochromism is thus proposed because of the reversible conversion of ligand fields in manganese(II) complexes.

45 citations


Journal ArticleDOI
TL;DR: In this paper, single crystal X-ray structures of the Zn(II), Pt(II) and Zn2(μ-L)2(L) 2(L 2 ) complexes are reported.

41 citations


Journal ArticleDOI
TL;DR: In this article, sulfoxide-bridged dipyridyl ligands are used to give Cu-Me-DPSO, which exhibits photophysical properties typical with [Cu(disphosphine)(diimine)]+ complexes.
Abstract: Copper(I) complexes (Cu-DPSO and Cu-Me-DPSO) utilizing sulfoxide-bridged dipyridyl ligands are reported. Cu-DPSO demonstrates photophysical properties typical with [Cu(disphosphine)(diimine)]+ complexes, however with additional steric bulk in the 6- and 6′-positions of the diimine ligand to give complex Cu-Me-DPSO; the photophysics are greatly altered. This species is isolated as an amorphous powder (a-Cu-Me-DPSO) which emits yellow light; upon heating to 180 °C, a crystalline powder is formed (c-Cu-Me-DPSO) which shows a large bathochromic shift (>100 nm) in emission, and shows orange luminescence attributed to a flattening distortion of the complex away from a tetrahedral geometry. On cooling to −196 °C, c-Cu-Me-DPSO displays a reversible thermochromic solid-state emission, from orange at room temperature to yellow at low temperatures. Using solid-state variable temperature excitation and absorption data, this phenomenon is attributed to a change in coordination geometry about the copper atom in the exc...

38 citations


Journal ArticleDOI
TL;DR: A series of Zn(II) complexes based on 4-formylpyrazolone Schiff base derivatives have been synthesized and characterized by single crystal X-ray diffraction, 1H NMR, FT-IR, and photoluminescence studies.

31 citations


Journal ArticleDOI
TL;DR: In this article, two new binuclear Ag(I) complexes of the types, [Ag2(bbt)2](pic)2·2DMF 1 and [Ag 2(bmbt]2(p-coumarate)2]·2CH3OH 2, have been synthesized and characterized by elemental analysis, electrical conductivities, IR, UV-Vis spectral measurements and X-ray single crystal diffraction.

28 citations


Journal ArticleDOI
TL;DR: A new chalcogenide Na2ZnSnS4 has been successfully synthesized by using Na2S2 as reactive flux and first-principles calculation results reveal that the valence band maximum and conduction band minimum are mainly composed of S3p, Zn 3d orbitals and Sn 5s, S 3p orbitals, respectively.
Abstract: A new chalcogenide Na2ZnSnS4 has been successfully synthesized by using Na2S2 as reactive flux. Na2ZnSnS4 crystallizes in the tetragonal system with space group of I4. Its cell parameters are a = 6.4835(6) A and c = 9.134(1) A. The structure is a derivative of AgGaS2, in which the Ag+ ions are replaced by Na+ ions and the Ga3+ ions are replaced by Zn2+ and Sn4+ ions. All three cations are in seriously distorted tetrahedral geometry with a distortion factor (η = c/ a) of 1.4. Optical measurements show that the Na2ZnSnS4 powder sample has a large transparent range from 0.8 to 25 μm and a wide band gap of 3.1 eV. It exhibits large second-harmonic generation intensity of 0.9 × AgGaS2 in the grain size range from 41 to 74 μm. First-principles calculation results reveal that the valence band maximum and conduction band minimum are mainly composed of S 3p, Zn 3d orbitals and Sn 5s, S 3p orbitals, respectively.

25 citations


Journal ArticleDOI
TL;DR: The luminescent properties of four-coordinate Au(i) complex (5) possessing a tetrahedral geometry are discussed on the basis of the emission spectra and decay times measured in a temperature range of 309-77 K.
Abstract: The synthesis and photoluminescence properties of three-coordinate Au(I) complexes with rigid diphosphine ligands LMe {1,2-bis[bis(2-methylphenyl)phosphino]benzene}, LEt {1,2-bis[bis(2-ethylphenyl)phosphino]benzene}, and LiPr {1,2-bis[bis(2-isopropylphenyl)phosphino]benzene} are investigated. The LMe and LEt ligands afford two types of complexes: dinuclear complexes [μ-LMe(AuCl)2] (1d) and [μ-LEt(AuCl)2] (2d) with an Au(I)–Au(I) bond and mononuclear three-coordinate Au(I) complexes LMeAuCl (1) and LEtAuCl (2). On the other hand, the bulkiest ligand, LiPr, affords three-coordinate Au(I) complexes, LiPrAuCl (3) and LiPrAuI (4), but no dinuclear complexes. X-ray analysis suggests that both 3 and 4 possess a highly distorted trigonal planar geometry. Moreover, luminescence data reveal that at room temperature, 3 and 4 exhibit yellow-green thermally activated delayed fluorescence in the crystalline state with maximum emission wavelengths at 558 and 549 nm, respectively. The emission yields are close to unity. Quantum chemical calculations suggest that the emission of 4 originates from the (σ + X) → π* excited state that possesses strong intraligand charge-transfer character. The luminescent properties of four-coordinate Au(I) complex (5) possessing a tetrahedral geometry are discussed on the basis of the emission spectra and decay times measured in a temperature range of 309–77 K.

24 citations


Journal ArticleDOI
01 Mar 2018-Minerals
TL;DR: In this article, the inner-sphere complex geometries of arsenate on hydrated alumina surfaces are modeled at the density functional theory (DFT)-continuum solvent level.
Abstract: Atomistic modeling of mineral–water interfaces offers a way of confirming (or refuting) experimental information about structure and reactivity. Molecular-level understanding, such as orbital-based descriptions of bonding, can be developed from charge density and electronic structure analysis. First-principles calculations can be used to identify weaknesses in empirical models. This provides direction on how to propose more robust representations of systems of increasing size that accurately represent the underlying physical factors governing reactivity. In this study, inner-sphere complex geometries of arsenate on hydrated alumina surfaces are modeled at the density functional theory (DFT)–continuum solvent level. According to experimental studies, arsenate binds to alumina surfaces in a bidentate binuclear (BB) fashion. While the DFT calculations support the preference of the BB configuration, the optimized geometries show distortion from the ideal tetrahedral geometry of the arsenic atom. This finding suggests that steric factors, and not just coordination arguments, influences reactivity. The Osurf–As–Osurf angle for the more favorable arsenate configurations is closest to the ideal tetrahedral angle of 109.5°. Comparing the results of arsenate adsorption using a small cluster model with a periodic slab model, we report that the two model geometries yield results that differ qualitatively and quantitatively. This relates the steric factors and rigidity of the surface models.

22 citations


Journal ArticleDOI
TL;DR: In this paper, the synthesis of N,C-coordinated organoboron compounds (B1-B4) based on phenanthroimidazole was described.

Journal ArticleDOI
TL;DR: The polymerization results showed that 1-5 in the presence of BnOH proceeded efficiently and their catalytic behaviors toward the ROP of ε-CL were significantly affected by the substituents of the aryl ring (Ar) on the end of the enamino framework, where the placement of electron-withdrawing substituent caused higher catalytic activity.
Abstract: A series of β-quinolyl-enamino aluminium complexes [AlLMe2] 1-7 {L = [(2-C9H6N)-CH[double bond, length as m-dash]C(4-MeC6H4)-N(Ar)-], Ar = C6H5 (1), 4-FC6H4 (2), 3,4,5-F3C6H2 (3), C6F5 (4), 5-tBuC6H4 (5), 2,6-Me2C6H3 (6), and 2,6-iPr2C6H3 (7)} were synthesized by the reaction of AlMe3 with the corresponding β-quinolyl-enamine ligands All the complexes were characterized by 1H and 13C NMR spectroscopy and elemental analysis The molecular structures of complexes 1-3 and 7 were confirmed by single-crystal X-ray diffraction, which revealed that all the Al atoms adopt a distorted tetrahedral geometry These Al complexes were tested as the initiators for the ring-opening polymerization (ROP) of e-caprolactone (e-CL) The polymerization results showed that 1-5 in the presence of BnOH proceeded efficiently and their catalytic behaviors toward the ROP of e-CL were significantly affected by the substituents of the aryl ring (Ar) on the end of the enamino framework, where the placement of electron-withdrawing substituents caused higher catalytic activity However 6 and 7 displayed poor activity under the same conditions, suggesting that ortho-substituents on the Ar moieties hamper the coordination-insertion of the e-CL monomer The ROP of e-CL by efficient binary catalytic systems proceeded in a living manner evidenced by the narrow PDIs and the linear nature of Mnversus conversion plots and monomer/catalyst ratios

Journal ArticleDOI
TL;DR: The voltage-gated proton channel (Hv1/VSOP) is inhibited by Zn2+, of which the binding site is located in the extracellular region and the most probable coordination structure was proposed as a tetrahedral geometry with ligands of carboxylate and imidazole groups in addition to a water molecule
Abstract: The voltage-gated proton channel (Hv1/VSOP) is inhibited by Zn2+, of which the binding site is located in the extracellular region. We utilized attenuated total reflection–Fourier transform infrared (ATR-FTIR) spectroscopy to examine the coordination structure by monitoring protein structural changes induced by Zn2+-binding. The Zn2+-induced difference ATR-FTIR spectra of Hv1 showed IR features that can be assigned to the histidine C5–N1 and carboxylate-COO– stretches as well as amide I changes likely in α-helical peptide bonds. Analysis of vibrational frequencies indicated that the Zn2+ is coordinated by the anionic carboxylate with monodentate mode and by the histidine at N1 (Nτ) position of the neutral imidazole form. Combined with quantum chemical calculations, the most probable coordination structure was proposed as a tetrahedral geometry with ligands of carboxylate and imidazole groups in addition to a water molecule.

Journal ArticleDOI
TL;DR: The results suggest that o-carborane-incorporated Co(II) complexes are worthwhile candidates for experimental exploration as single-ion molecular magnets.
Abstract: We analyze the magnetic properties of three mononuclear Co(II) coordination complexes using quantum chemical complete active space self-consistent field and N-electron valence perturbation theory approaches. The complexes are characterized by a distorted tetrahedral geometry in which the central ion is doubly chelated by the icosahedral ligands derived from 1,2-(HS)2-1,2-C2B10H10 (complex I), from 1,2-(HS)2-1,2-C2B10H10 and 9,12-(HS)2-1,2-C2B10H10 (complex II), and from 9,12-(HS)2-1,2-C2B10H10 (complex III), which are two positional isomers of dithiolated 1,2-dicarba-closo-dodecaborane (complex I). Complex I was realized experimentally recently (Tu, D.; Shao, D.; Yan, H.; Lu, C. Chem. Commun. 2016, 52, 14326) and served to validate the computational protocol employed in this work, while the remaining two proposed complexes can be considered positional isomers of I. Our calculations show that these complexes present different axial and rhombic zero-field splitting anisotropy parameters and different values...

Journal ArticleDOI
TL;DR: The Schiff base ligand, N′-(1-{6]-1-(Benzyloxycarbonyl-hydrazono)-ethyl]-pyridin-2-yl}-ethylidene)-hydrazinecarboxylic acid benzyl ester (bc2-dap), was synthesized by the reaction of 2,6-diacetylpyridine (dap) with benzyl carbazate (bc) in methanol as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this paper, the tetradentate mode of coordination of the ligand L and its complexes 1-3 was characterized on the basis of physico-chemical and spectral (FT-IR, Mass, 1H, 13C, DEPT and 77Se NMR) studies.

Journal ArticleDOI
TL;DR: In this article, four and five-coordinate high-spin (S = 2) Fe(II) complexes bearing the pyrrolyl-derived tBuPNP pincer ligand were characterized by X-ray diffraction and zero-field 57Fe Mossbauer spectroscopy.

Journal ArticleDOI
TL;DR: The results of this effort show that increasing steric bulk and electron donation properties on the nitrogen ancillary ligand will improve the nitrite reduction ability of the copper(i)-nitro model complexes.
Abstract: Two copper(I)–nitro complexes [Tpm3-tBuCu(NO2)] (1) and [(Ph3P)2N][Tp3-tBuCu(NO2)] (2), containing steric bulky neutral tris(3-tert-butylpyrazolyl)methane and anionic hydrotris(3-tert-butylpyrazolyl)borate ligands, have been synthesized and characterized. Complex 2 adopts a unique κ2-binding mode of Tp3-tBu around the copper(I)–nitro environment in the solid state and shows a four-coordinated tetrahedral geometry surrounded by a nitro and three pz3-tBu groups in solution. Both complexes 1 and 2 allow for the stoichiometric reduction of NO2− to NO with H+ addition. The results of this effort show that increasing steric bulk and electron donation properties on the nitrogen ancillary ligand will improve the nitrite reduction ability of the copper(I)–nitro model complexes.

Journal ArticleDOI
TL;DR: In this article, a tetranuclear copper (II) Schiff base complex bridged by 2,6-bis-[(2-hydroxyethylimino)methyl]-4-methylphenol, namely [Cu4(L1)2(O)(OAc)4] was synthesized.
Abstract: A water-soluble tetranuclear copper (II) Schiff base complex bridged by 2,6-bis-[(2-hydroxyethylimino)methyl]-4-methylphenol, namely [Cu4(L1)2(O)(OAc)4].2H2O was synthesized. The complex was characterized by 1HNMR, FT-IR, elemental analyses and single-crystal X-ray diffraction. The crystal structure analyses revealed that four Cu atoms were located around a central O atom in a distorted tetrahedral geometry. Beside the two ligands, four acetates also bridged the four Cu atoms. The interaction of the complex with Bovine serum albumin (BSA) was explored by absorption and emission titration methods the calculated binding constants revealed high affinity of the complex to BSA. The antitumor activity of the complex against Jurkat, Raji and A549 cell lines was assessed by the MTT colorimetric method. A strong activity against the cultured tumor cells was observed which makes the complex a possible candidate as an anticancer agent. Further investigation of the BSA-complex interactions was done by docking studies.

Journal ArticleDOI
TL;DR: In this paper, the intrinsic binding constants of bis-benzimidazole ligands and complexes were determined using absorption spectral titrations, and it was shown that they exhibit π-π stacking interactions that hold their supramolecular arrangement.

Journal ArticleDOI
TL;DR: In this paper, a colorless Cu(I) complexes of composition [CuCl(PPh3)2(LR)] were characterized by spectroscopic methods and further studied by single crystal X-ray diffractometry.

Journal ArticleDOI
TL;DR: Crystalline molecular C(CN)4 starts to polymerize above ∼7 GPa and transforms into an interconnected disordered network, which is recoverable to ambient conditions, and demonstrates feasibility for the pressure-induced polymerization of molecules with premeditated functionality.
Abstract: Tetracyanomethane, C(CN)4, is a tetrahedral molecule containing a central sp3 carbon that is coordinated by reactive nitrile groups that could potentially transform to an extended CN network with a significant fraction of sp3 carbon. High-purity C(CN)4 was synthesized, and its physiochemical behavior was studied using in situ synchrotron angle-dispersive powder X-ray diffraction (PXRD) and Raman and infrared (IR) spectroscopies in a diamond anvil cell (DAC) up to 21 GPa. The pressure dependence of the fundamental vibrational modes associated with the molecular solid was determined, and some low-frequency Raman modes are reported for the first time. Crystalline molecular C(CN)4 starts to polymerize above ∼7 GPa and transforms into an interconnected disordered network, which is recoverable to ambient conditions. The results demonstrate feasibility for the pressure-induced polymerization of molecules with premeditated functionality.

Journal ArticleDOI
TL;DR: In this paper, the structure of complex 1 was determined by single crystal X-ray diffraction and the asymmetric unit of complex consists of one Ag(I) center bonded to one 2,6-pydcH2 and one deprotonated 2.6pydcaH2 with two water molecules acting as guest molecules connecting the discrete molecules of the complex 1.

Journal ArticleDOI
TL;DR: In this article, a high-resolution line-by-line intensity measurement for the strong fundamental band observed near 10μm, associated with the excitation of the infrared active stretching mode ν3, is presented.
Abstract: Ruthenium tetroxide (RuO4) is a heavy tetrahedral molecule characterized by an unusual volatility near ambient temperature. Because of its chemical toxicity and the radiological impact of its 103Ru and 106Ru isotopologues, the possible remote sensing of this compound in the atmosphere has renewed interest in its spectroscopic properties. The present contribution is the first investigation dealing with high-resolution line-by-line intensity measurements for the strong fundamental band observed near 10 μm, associated with the excitation of the infrared active stretching mode ν3. It relies on new, high resolution FTIR spectra recorded at room temperature, using a specially constructed cell and an isotopically pure sample of 102Ru16O4. Relying on an effective Hamiltonian and associated effective dipole moment [S Reymond–Laruinaz et al, J Mol Spectrosc 2015;315:46–54], the measured line intensities were assigned and dipole moment parameters determined. A HITRAN-formatted frequency and intensity line list was generated.

Journal ArticleDOI
TL;DR: In this paper, the authors explored the probable parameters responsible for the potent anticancer activity of tin-based organometallic compounds and identified the characteristic structural, electronic, and reactivity features of some recently synthesized triorganotin(IV) carboxylates by employing the density functional theory.
Abstract: The present work explores the probable parameters responsible for the potent anticancer activity of tin-based organometallic compounds. The characteristic structural, electronic, and reactivity features of some recently synthesized triorganotin(IV) carboxylates are identified by employing the density functional theory (DFT). The influence of solvent on these parameters is analyzed. In general, the stability of the complex is found to be governed by the donor ligand, alkyl/aryl group at the tin center, and the dielectric of the medium. Gallic acid, best known for its antioxidant and apoptosis inducing ability, forms the most stable complexes with tetrahedral geometry. The NBO analysis, frontier orbitals, and various reactivity indices of the complexes are discussed in detail. The most reactive sites on the organotin complexes are also predicted.

Journal ArticleDOI
TL;DR: In this paper, the salt metathesis reaction of CuI with two sodium precursors (NaBb and NaBb-1) of bipodal scorpionate type ligands [Bb = dihydrobis(2-mercapto-benzimidazolyl)borate, (Bb 1 = dihedrobis (2-mbrnothiazolyl), and (bb-bb)-1 = dihdris(1)-dihydrobis-dihyboris(
Abstract: The salt metathesis reaction of CuI with two sodium precursors (NaBb and NaBb-1) of bipodal scorpionate type ligands [Bb = dihydrobis(2-mercapto-benzimidazolyl)borate, (Bb-1 = dihydrobis(2-mercapto-benzothiazolyl)borate)] has been explored in the presence of selected phosphine ligands (PPh3, PCy3, PPh2Me, PPh2Py). All of the resulting Cu(I) complexes were formed as predominantly a single monomeric isomer and were characterized using a combination of 1H, 13C{1H}, and 31P{1H} NMR spectroscopy, and in two cases by X-ray crystallography. In the X-ray crystal structure of complexes 1 and 6, the Cu(I) center adopts a distorted tetrahedral geometry. Complexes 1 and 6 exhibit (B)H⋯Cu distances of 2.008 A and 1.866 A length, respectively. Based on IR spectroscopy and X-ray crystallography data, 1 and 6 adopt a κ3-S,S,H coordination mode in the solid state. All the metal complexes were screened for their photoluminescence properties in the solid state at different temperatures (298 K and 77 K). These complexes feature emission bands at room temperature in the range 527–571 nm, among which complex 3 and complex 6 reveal stronger thermochromic behavior at lower temperature. The data from the X-ray crystallography studies for 1 and 6 were used to optimize their structures computationally. Density Functional Theory (DFT) analyses were also conducted on the optimized structures to learn about the sources of electronic transitions in these complexes.

Journal ArticleDOI
TL;DR: In this paper, a single X-ray analysis showed that fluorine anions and water molecules are H-bonded to each other in an alternating fashion within the fluorine-water hybrid cluster, where a fluorine ion plays the important role of connecting the host metal complex and guest water cluster.
Abstract: Three crystalline complexes containing fluorine anion water clusters, [Cd(Im)6][F·H2O]2 (1), [Ni(Im)6][F2·(H2O)5] (2) and [Co(Im)6][F·NO3·(H2O)4] (3), were reported. The interesting fluorine anion water clusters are described in this paper. Single X-ray analysis shows that fluoride ions in the water clusters have different coordination environments, four-coordinated in a tetrahedral geometry for (1), five-coordinated in a trigonal bipyramidal geometry for (2), and three-coordinated in a planar trigonal geometry for (3). F−(H2O)n is assembled by strong H-bonding interactions [OH⋯F = 2.576(1)–2.813(1) A], where a fluoride anion plays an important role in connecting an imidazole ligand of the host [M(Im)6]2+. The strength of an ionic bond between the host and guest is strongly influenced by the F−(H2O)n water cluster adjacent to the ligand with NH⋯F distances of 2.607–2.755 A. The TGA, IR and XRD studies for the above three compounds at different testing temperatures suggested that the fluorine anion water cluster, F−(H2O)n, was very stable. This result distinctly differentiates these compounds from the reported ones containing neutral water cluster molecules. This phenomenon indicated the stronger anionic hydrogen-bond interaction between F− and H2O, which also confirmed the intracluster proton transfer process F−·H2O → HF·OH−. This result suggests that the fluorine anions and water molecules are H-bonded to each other in an alternating fashion within the fluoride−water hybrid cluster, where a fluorine anion plays the important role of connecting the host metal complex and guest water cluster.


Journal ArticleDOI
TL;DR: In this paper, a 8-hydroxyquinoline derivative, named 8-hexoxyquinoline-2-carboxaldehyde 2-furoyl hydrazone (HQFUH), was obtained, which was successfully synthesized as well as its respective Zn(II) coordination compound.

Journal ArticleDOI
TL;DR: In this article, the molecular geometries, HOMO-LUMO analysis and molecular electrostatic potential of compounds 1 and 2 were investigated by theoretical calculations using B3LYP functional with the 6-311G basis combination set in the ground state and compared with the experimental values.