Triclinic Space Group Research Articles

The Coordination Between Pedal and Finger Forces During Piano Playing in Classical Passage With Respect to the Quality of Sound

A novel hybrid organic-inorganic molecular solid, 1-(4-methoxyphenyl)piperazinium (1–4MPPip) tetra(isothiocyanate)cobalt monohydrate (1–4MPPip)4[Co(NCS)4]2•H2O (I), was prepared using a slow evaporation growth technique at room temperature and characterized by elemental analysis, X-ray crystal structure, spectroscopic and computational studies. The crystal structural analysis reveals that the solid crystallizes in the triclinic space group P1¯. The [Co(NCS)4]2− anions are arranged in pairs along the c-axis direction to form anionic layers parallel to the (a,c) plane. Intermolecular interactions were investigated by Hirshfeld surfaces and contact enrichment tools. The organic entities are grouped into dimers through weak interactions OW-H…N and OW-H…O generated by the water molecules. The robustness of the crystal is also enhanced by CH…π and CH…S intermolecular interactions. Mulliken charge distribution, molecular electrostatic potential (MEP) maps and HOMO and LUMO energy gaps have been computed. The vibrational absorption bands were identified by infrared spectroscopy. The solid-state UV-Visible absorption spectrum of the title compound was obtained at room temperature in order to spotlight the optical properties.

Group II complexes of N- and O-donors Mixed-ligands as anticancer agents

Reactions of 1,10-phenanthroline (phen), p-amino benzoic acid (paba) and cinnamic acid (cina) with MCO3 (M = Mg, Ca, Sr) yielded two mononuclear magnesium complexes [{Mg(phen)(H2O)4}(phen)(paba)2] (1) and [{Mg(phen)(H2O)4}(phen)(cina)2] (2) and two one dimensional chains of both calcium and strontium [Ca(phen)(cina)]n (3), and [Sr(phen)(cina)]n (4) respectively. The structures were characterized by a variety of analytical techniques including IR, UV–Vis, 1H NMR, elemental analysis, and single crystal X–ray diffraction analysis. In these complexes, phen binds via an N,Ń–chelate pocket, while the monoanionic paba—/cina— ligands either remains uncoordinated (in case of 1 and 2) or coordinated in a tridentate fashion (in case of 3 and 4). Complexes 1, 3 and 4 crystallize in the same orthorhombic space group Pbcn while complex 2 crystallizes in triclinic space group P1. In complex 1 and 2, Mg2+ cation adopts a distorted six-coordinate octahedral geometry comprising an [N2O4] donor set while in complexes 3 and 4, Ca2+ and Sr2+ cations adopt a distorted eight-coordinate geometry comprising [N2O6] donor sets. Complexes 1, 2 and 4 were found to be potent anticancer against oral cancer cell line i.e. CAL-27 with IC50 1.85 ± 0.11 , 2.98 ± 1.2 and 5.05 ± 0.35 respectively while complex 3 was inactive.

Guest-Mediated Hierarchical Self-Assembly of Dissymmetric Organic Cages to Form Supramolecular Ferroelectrics

Guest-Mediated Hierarchical Self-Assembly of Dissymmetric Organic Cages to Form Supramolecular Ferroelectrics

Polyoxometalate-like structure of new potassium triphenylsiloxides: [K6(OSiPh3)6(C3H7OH)(H2O)]·2C6H5CH3 and [K6(OSiPh3)6(H2O)2

The synthesis and structural characterization of two new potassium triphenylsiloxides, namely, aqua(propan-2-ol)hexakis(triphenylsilanolato)hexapotassium toluene disolvate, [K6(C18H15OSi)6(C3H8O)(H2O)]·2C7H8, and diaquahexakis(triphenylsilanolato)hexapotassium, [K6(C18H15OSi)6(H2O)2], are reported. Both compounds crystallize in the triclinic space group P-1. The structure in each case resembles an alkali metal polyoxometalate-like structure, in which electrostatic interactions are observed in the metal-oxygen core. Furthermore, both compounds also resemble a reverse micelles-like architecture, in which the hydrophilic core is enclosed in a hydrophobic shell. The cores of the complexes are flanked by hydrophobic aromatic rings derived from Ph3SiO- anions, where intramolecular π-interactions between the aromatic rings and potassium cations stabilize the cores of the crystals. Moreover, in both structures, the presence of hydrogen bonds is observed; until now, no crystal structures have been described containing K atoms and triphenylsiloxide molecules in which the presence of hydrogen bonds was confirmed. Thus, these coordination entities could be considered as attractive reagents for further synthetic protocols towards heterometallic complexes.

Synthesis and X-ray Crystal Structure of New Substituted 3-4′-Bipyrazole Derivatives. Hirshfeld Analysis, DFT and NBO Studies

A new compounds named 3-4′-bipyrazoles 2 and 3 were synthesized in high chemical yield from a reaction of pyran-2,4-diketone 1 with aryl hydrazines under thermal conditions in MeOH. Compound 2 was unambiguously confirmed by single-crystal X-ray analysis. It crystalizes in a triclinic crystal system and space group P-1. Its crystal structure was found to be in good agreement with the spectral characterizations. With the aid of Hirshfeld calculations, the H…H (54.8–55.3%) and H…C (28.3–29.2%) intermolecular contacts are the most dominant, while the O…H (5.8–6.5%), N…H (3.8–4.6%) and C…C (3.0–4.9%) are less dominant. The compound has a polar nature with a net dipole moment of 6.388 Debye. The BD(2)C31-C32→BD*(2)N4-C34 (27.10 kcal/mol), LP(1)N5→BD*(2)C31-C32 (36.90 kcal/mol), BD(1)C32-C34→BD*(1)C18-C31 (6.78 kcal/mol) and LP(1)N4→BD*(1)N5-C31 (7.25 kcal/mol) are the strongest π→π*, n→π*, σ-σ* and n→σ* intramolecular charge transfer processes, respectively.

Binding of periodate by non–covalent interaction: Synthesis, characterization, single crystal structure determination, antibacterial and anticancer studies of [Co(bpy)2CO3].IO4

The facile and effective synthesis of novel cobalt (III) complex salt of composition [Co(bpy)2CO3].IO4 (where bpy=2,2’-bipyridine, IO4= periodate) was performed in aqueous medium at room temperature. The complex was characterized with wide range of analytical and spectroscopic tools such as CHN, FT-IR, UV–Vis and 1H NMR. The complex salt crystallizes in triclinic space group (P-1) with a=7.17687(12), b= 10.8056(2), c= 14.3822(3)Å, α=83.4356(17)°, β=85.3108(15)°, γ=86.2535(16)°, V=1102.56(4)Å3 and Z=2. The single-crystal X-ray diffraction studies revealed that the complex is six coordinated with the inner coordination sphere of the metal ion comprising of one carbonate and two 2,2’-bipyridine moieties. The crystal has distorted octahedral geometry with hydrogen bonding interactions [C‒Hδ+···Oanionδ−] existing in the crystal lattice. The thermogravimetric studies were performed to further support the coordination structure of the complex. In addition, the complex was tested for in vitro antibacterial activity against Gram-positive (S. aureus) and Gram-negative bacteria (E.coli and P. aeruginosa). The complex showed significant activity against all three bacteria tested, however S. aureus was found to be more sensitive to it, with MIC of 400 µM. Further, the complex showed good anti-cancer potential as it was able to reduce the viability of HeLa cells in a concentration dependent manner with IC50 value corresponding to 60 µM.

Theoretical Modeling (Sparkle RM1 and PM7) and Crystal Structures of the Luminescent Dinuclear Sm(III) and Eu(III) Complexes of 6,6,7,7,8,8,8- Heptafluoro-2,2-dimethyl-3,5-octanedione and 2,3-Bis(2-pyridyl)pyrazine: Determination of Individual Spectroscopic Parameters for Two Unique Eu3+ Sites.

Heteroleptic homo dinuclear complexes [Sm(fod)3(μ-bpp)Sm(fod)3] and [Eu(fod)3(μ-bpp)Eu(fod)3] and their diamagnetic analogue [Lu(fod)3(μ-bpp)Lu(fod)3] (fod is the anion of 6,6,7,7,8,8,8- heptafluoro-2,2-dimethyl-3,5-octanedione (Hfod) and bpp is 2,3-bis(2-pyridyl)pyrazine) are synthesized and thoroughly characterized. The lanthanum gave a 1:1 adduct of La(fod)3 and bpp with the molecular formula of [La(fod)3bpp]. The 1H NMR and 1H-1H COSY spectra of the complexes were used to assign the proton resonances. In the case of paramagnetic Sm3+ and Eu3+ complexes, the methine (of the fod moiety) and the bpp resonances are shifted in the opposite direction and the paramagnetic shifts are dipolar in nature, which decrease with increasing distance of the proton from the metal ion. The single-crystal X-ray analyses reveal that the complexes (Sm3+ and Eu3+) are dinuclear and crystallize in the triclinic P1 space group. Each metal in a given complex is eight coordinate by coordinating with six oxygen atoms of three fod moieties and two nitrogen atoms of the bpp. Of the two metal centers, in a given complex, one has a distorted square antiprism arrangement and the other acquires a distorted dodecahedron geometry. The Sparkle RM1 and PM7 optimized structures of the complexes are also presented and compared with the crystal structure. Theoretically observed bond distances are in excellent agreement with the experimental values, and the RMS deviations for the optimized structures are 2.878, 2.217, 2.564, and 2.675 Å. The photophysical properties of Sm3+ and Eu3+ complexes are investigated in different solvents, solid, and PMMA-doped thin hybrid films. The spectroscopic parameters (the Judd–Ofelt intensity parameters, radiative parameters, and intrinsic quantum yield) of each Eu3+ sites are calculated using the overlap polyhedra method. The theoretically obtained parameters are close to the experimental results. The lifetime of the excited state is 38.74 μs for Sm3+ and 713.62 μs for the Eu3+ complex in the solid state.

Synthesis, crystal structure, optical, thermal and magnetic studies of a new organic-inorganic hybrid based on tetrachloroferrate (III)

A new organic metal halide hybrid, benzyltrimethylammonium tetrachloroferrate (III), 1, ((BzMe3N)FeCl4) was synthesized by slow evaporation. The single crystal X-ray diffraction reveals that 1, crystallizes in the P-1 triclinic space group with the parameters a ​= ​7.158 (5), b ​= ​8.814 (8), c ​= ​12.922 (4) Å, α ​= ​82.44 (5), β ​= ​86.14 (4), γ ​= ​87.13 (7)°, V ​= ​805.7 (10) Å3 and Z ​= ​2. The structure packing exhibits a cationic and anionic layers alternation linked by means of C─H⋯Cl hydrogen interactions. The Hirshfeld surface and the lattice energy of 1 were calculated. The material purity was verified using X-ray powder diffraction and Rietveld refinements. The TG-DTA analysis revealed that the new compound is stable up to 250 ​°C. The UV–Visible was the fluorescence emission were investigated. The optical band gap energy was deduced from the Kulbeka-Munk spectrum. The HOMO-LUMO gap was calculated theoretically. The studied material shows weak antiferromagnetic behavior.

Three metal(II) complexes constructed using the 2-(1H-benzo[d]imidazol-2-yl)quinoline ligand

Abstract 2-(1H-benzo[d]imidazol-2-yl)quinoline (BQ) as ligand and three coordination compounds of formula {Zn(BQ)Cl2} (1), {Pb(BQ)Cl2} n (2) and {[Cu(BQ)2(OC(O)CH3)]OC(O)CH3 · CH3COOH} (3) have been synthesized and fully characterized. The complexes crystallize in triclinic space group P 1 ‾ $P‾{1}$ . In complexes 1 and 2, the coordination geometry is a distorted tetrahedral environment around the zinc center and a distorted sixfold coordination geometry around the lead center, respectively. In complex 3 the central Cu(II) center is in a trigonal bipyramidal coordination geometry. The Cu(II) ion is surrounded by two bidentate 2-(2′-quinolyl)benzimidazole (BQ) ligands and one coordinated acetate molecule. One further acetate anion associated by a strong hydrogen bond with a molecule of acetic acid balances the charge of the compound.

Synthesis, characterization and DNA binding of four imidazo[4,5-f]1,10-phenanthroline derivatives

The synthesis and crystal structures of four imidazo[4,5- f ]1,10-phenanthroline type compounds, namely 2,6-(dimethoxypyridyl)imidazo[4,5- f ]1,10-phenanthroline monohydrate (C 20 H 17 N 5 O 3 ) 1a , (indole)imidazo[4,5- f ]1,10-phenanthroline ethanol monosolvate monohydrate (C 23 H 21 N 5 O 2 ) 2a , (benzo[b]thiophene)imidazo[4,5- f ]1,10-phenanthroline (C 21 H 12 N 4 S) 3 , and (4,5-dimethylthiophene)imidazo[4,5- f ]1,10-phenanthroline (C 19 H 14 N 4 S) 4 , are reported. The compounds were characterized in dimethyl sulfoxide- d 6 (DMSO- d 6 ) solution by 1 H and 13 C NMR spectroscopy and in the solid-state by 13 C NMR spectroscopy using the cross-polarisation magic angle spinning (CP/MAS) technique. 1 H and 13 C liquid-state NMR spectra of 1 and 2 exhibit a sharpening of peaks upon heating, suggesting the presence of two tautomeric forms of 1 and 2 , this is confirmed by the presence of two distinct signals for the N-H protons in the 1 H spectra. This tautomeric effect was not observed in 3 and 4. 1a crystallised in the triclinic space group, P 1 ¯ with one molecule and one solvent water molecule in the asymmetric unit while 2a crystallised in the monoclinic space group, P 2 1 / c, with one molecule and two solvate molecules (CH 3 CH 2 OH and H 2 O) in the asymmetric unit. 3 and 4 both crystallised in the monoclinic space group, P 2 1 / n, each with one molecule in the asymmetric unit. 4 displays a positional disorder on the 4,5-thiophene moiety in a 60:40 ratio. When a drug candidate binds to DNA via intercalation, a hypochromic effect is observed in the spectra due to stabilised π-interactions between the base pairs of the DNA structure and the drug candidate. Contrastingly, if a drug candidate binds to DNA via electrostatic attraction, a hyperchromic effect is observed. The mode of binding as well as intrinsic binding constant (K b ) of 1a – 4 are reported herein. The spectra of 1a, 2a and 4 exhibit a hypochromic effect, thus interaction via π-interactions is suggested and the spectrum of 3 exhibits a hyperchromic shift, suggesting that the mode of binding of 3 occurs via electrostatic attraction. The K b values for 1a–4 range from 1.5 × 10 3 – 1.7 × 10 4 M −1 .

A novel manganese(II) bisthiocarbohydrazone complex: Crystal structures, Hirshfeld surface analysis, DFT and molecular docking study with SARS-CoV-2

A novel Mn(II) complex [Mn(H2L)Cl2]•H2O (1) of a ditopic ligand 1,5-bis(2-benzoylpyridine) thiocarbohydrazone (H2L) was synthesized and characterised physico-chemically. A part of the mother solution of the complex 1 and THF yielded single crystals in a triclinic space group and are found same from the crystals obtained from another mixture of the mother solution and ethyl acetate. Single crystal XRD studies have confirmed the mononuclear complex formation and absence of any interactions between the Mn(II) centers. A solution of the complex 1 in chloroform, conversely, yielded a crystallographically different complex [Mn(H2L)Cl2]•CHCl3 (1a) in monoclinic and is also characterised with single crystal XRD. The ligand is coordinated through thione sulfur atom to form a square pyramidal geometry around Mn(II) center in both the complexes. The molecular packing of the complexes is found influenced by the nature of solvent inclusion, and are stabilized by different non-covalent interactions in the lattice. The intermolecular interactions are quantified by Hirshfeld surface analyses, which reveal that H•••Cl interactions has maximum contribution to the total Hirshfeld surface in the complex 1a. This is the first crystal structure study of a manganese(II) complex of a bisthiocarbohydrazone ligand. The molecular and electronic structures of the complexes are studied by DFT quantum chemical calculations. The band gap (Eg) of the complex 1 was estimated as 2.45 eV using Kubelka-Munk model and is in agreement with the electronic spectral calculations of the complex at TD-DFT level. Molecular docking studies of both the ligand and the complex reveal their greater propensity towards SARS-CoV-2 main protease compared to B-DNA dodecamer. Also, the binding potential of the ligand and the complex with SARS-CoV-2 main protease is found higher than that with chloroquine and hydroxychloroquine.

Cationic iridium (III) complexes bearing fluorinated Ar-BIAN ligands: Synthesis, structure, electronic, and electrochemical properties

Three cationic iridium (III) complexes, [(ppy)2Ir(4-FPhBIAN)]PF6 (Ir1), [(ppy)2Ir(3,4-F,FPhBIAN)]PF6 (Ir2), [(ppy)2Ir(4-CF3PhBIAN)]PF6 (Ir3) were synthesized from 2-phenylpyridine (Hppy) as cyclometalating ligand and N,N′-bis(aryl)acenaphthene as ancillary ligand. All the complexes were characterized by FT-IR, 1H, 13C and 19F NMR spectroscopies, and elemental analysis. The molecular structures of the complexes were determined by X-ray crystallography. These complexes were crystalized as greenish-black needles in the triclinic P1 space group for complexes Ir1 and Ir3, while Ir2 was crystalized in the orthorhombic P212121 space group. Electrochemical properties were studied by cyclic voltammetry analysis. All the complexes showed quasi-reversible oxidation and reduction peaks, and reversibility increased by scan rate. Electronic properties were studied by UV-visible spectroscopy, and intense absorption band below 300 nm was obtained compared to intense absorption bands between 300 ~ 530 nm. Density functional theory (DFT) calculations were employed to get better understanding of electrochemical properties.

Crystal structures of bis-{N-[1-(pyridin-2-yl-κN)ethylidene]nicotine hydrazide-κ2N’,O}cobalt(II)bis(perchlorate) dihydrate and bis-{N'-[1-(pyridin-2-yl-κN)ethylidene]nicotinohydrazide-κ2N',O}copper(II) perchlorate

Complexes of Co(II), [Co(C26H24N8O2)]·(ClO4)2·(H2O)2 (1), and Cu(II), [Cu(C26H23N8O2)]·(ClO4) (2), have been synthesized. The prepared two compounds were characterized by elemental analysis, infrared and their structures were determined by single-crystal X-ray diffraction. The compound 1 crystallizes in the triclinic space group P-1 with the following unit cell parameters: a = 8.880 (5) Å, b = 10.529 (5) Å, c = 18.430 (5) Å, α = 99.407 (5)°, β = 102.174 (5)°, γ = 100.652 (5)°, V = 1618.2 (13) Å3, Z = 2, T = 293(2), μ(MoKα) = 0.77 mm-1, Dcalc = 1.582 g/cm3, 16135 reflections measured (5.050° ≤ 2q ≤ 59.152°), 7648 unique, Rint = 0.034 which were used in all calculations. The final R1 was 0.066 (I ≥ 2σ(I)) and wR2 was 0.22 (all data). The compound 2 crystallizes in the monoclinic space group P21/c with the following unit cell parameters : a = 11.652 (5) Å, b = 16.540 (5) Å, c = 14.512 (5) Å, β = 93.495 (5)°, V = 2791.6 (18) Å3, Z = 4, T = 293(2), μ(MoKα) = 1.05 mm-1, Dcalc = 1.768 g/cm3, 15592 reflections measured (5.624° ≤ 2θ ≤ 58.804°), 6630 unique, Rint = 0.025 which were used in all calculations. The final R1 was 0.050 (I ≥ 2σ(I)) and wR2 was 0.144 (all data). In both complexes, the ligand acts in a tridentate fashion. In the structure of the mononuclear complex 1, the Co(II) cation is coordinated by two ligand molecules. The basal plane around the Co(II) cation is occupied by two pyridine nitrogen atoms and two carbonyl oxygen atoms. Two imino nitrogen atoms occupy the apical positions of the distorted square-pyramidal geometry. The mononuclear 2 consists of a Cu(II) coordinated by one ligand and one monodeprotonated ligand molecule. The metal center lies in a distorted square bipyramidal environment. The basal plane around the Cu(II) is occupied by two pyridine nitrogen atoms and two carbonyl oxygen atoms, the apical position being occupied by the two imino nitrogen atoms.

Ternary Zinc Antimonides Unlocked Using Hydride Synthesis

Three new sodium zinc antimonides Na11Zn2Sb5, Na4Zn9Sb9, and NaZn3Sb3 were synthesized utilizing sodium hydride NaH as a reactive sodium source. In comparison to the synthesis using sodium metal, salt-like NaH can be ball-milled, leading to the easy and uniform mixing of precursors in the desired stoichiometric ratios. Such comprehensive compositional control enables a fast screening of the Na-Zn-Sb system and identification of new compounds, followed by their preparation in bulk with high purity. Na11Zn2Sb5 crystallizes in the triclinic P1 space group (No. 2, Z = 2, a = 8.8739(6) Å, b = 10.6407(7) Å, c = 11.4282(8) Å, α = 103.453(2)°, β = 96.997(2)°, γ = 107.517(2)°) and features polyanionic [Zn2Sb5]11- clusters with unusual 3-coordinated Zn atoms. Both Na4Zn9Sb9 (Z = 4, a = 28.4794(4) Å, b = 4.47189(5) Å, c = 17.2704(2) Å, β = 98.3363(6)°) and NaZn3Sb3 (Z = 8, a = 32.1790(1) Å, b = 4.51549(1) Å, c = 9.64569(2) Å, β = 98.4618(1)°) crystallize in the monoclinic C2/m space group (No. 12) and have complex new structure types. For both compounds, their frameworks are built from ZnSb4 distorted tetrahedra, which are linked via edge-, vertex-sharing, or both, while Na cations fill in the framework channels. Due to the complex structures, Na4Zn9Sb9 and NaZn3Sb3 compounds exhibit low thermal conductivities (0.97-1.26 W·m-1 K-1) at room temperature, positive Seebeck coefficients (19-32 μV/K) suggestive of holes as charge carriers, and semimetallic electrical resistivities (∼1.0-2.3 × 10-4 Ω·m). Na4Zn9Sb9 and NaZn3Sb3 decompose into the equiatomic NaZnSb above ∼800 K, as determined by in situ synchrotron powder X-ray diffraction. The discovery of multiple ternary compounds highlights the importance of judicious choice of the synthetic method.

Crystal structure, Hirshfeld surface and reactivity of novel ligand-LAT1 derived from dehydroacetic acid: intermolecular interactions with SARS-Cov-2/main protease

The crystals of new ligand, namely (3E)-6-methyl-3-{1-[(pyridin-3-ylmethyl) amino] ethylene}-2H-pyran-2, 4(3H)-dione) (LAT1), were synthesized using the evaporation solution technique. Single-crystal X-ray diffraction and physico-chemical characterization (ATR, proton and carbon-13 NMR and UV-Visible) of LAT1 were reported. In addition, Hirshfeld surface analysis (HSA) of the solid compound, structure optimization, Mulliken and NBO charges, global indices of reactivity, local reactivity descriptors and molecular electrostatic potential (MEP) of the ligand were investigated theoretically. XRD analysis showed that LAT1 crystallizes in the triclinic space group P-1 and the structure was stabilized through hydrogen bonds. HAS revealed that H…H (46.5%) and O…H (25.7%) contacts are in control of crystal stacking. The energy gap (4.679 eV) and reactivity descriptors indicate the stability of LAT1. The Mulliken and NBO charges showed that the protons have a positive charge and the heteroatoms exhibit negative charges. The Fukui function and MEP study revealed that the heteroatoms are the most reactive sites for an electophilic attack on the ligand. Molecular docking simulation shows that the significant binding affinity of LAT1 with SARS-CoV-2/Mpro is due to the formation of high number of hydrogen bonds.

Structural, spectroscopic studies, thermal proprieties and Hirshfeld surface analysis of a novel tetra-piperidinium disodium decavanadate nonahydrate

In this study, we focus on the synthesis of a new decavanadate, tetra-piperidinium disodium decavanadate nonahydrate, (C5H12N)2(C5H11N)2Na2V10O28·9H2O, obtained by slow evaporation method. The single crystal X-ray diffraction analysis indicates that the decavanadate compound crystallizes in the triclinic space group P-1. The structural study shows that the centrosymmetric decavanadate group [V10O28]6−, a disodium bridging unit based on the dimer Na2N2O4(H2O)4, four organic cations and five uncoordinated water molecules are linked through NH…O and OH…O hydrogen bonds, building up a 3D network. The phase purity of the title compound was analyzed by the Powder X-ray Diffraction (PXRD) pattern. The different functional groups were studied by Fourier Transform-Infrared (FT-IR) and Nuclear Magnetic Resonance (NMR) Spectroscopy. Additionally, the optical properties of the compound confirmed its semiconductor behavior. Thermal analyses such as Differential Scanning Calorimetry (DSC) and thermogravimetry (TG), were also carried out to determine the thermal stability of the compound. Moreover, the three-dimensional Hirshfeld surface projections (3D-HS) and their relative two-dimensional fingerprint plots (2D-FP) revealed that the structure is dominated by the intermolecular contacts O…H/H…O (43.6%) and H…H (34.1%).

Synthesis and structure of the λ 6Si-silicate [Cs(18-crown-6)]2[Si(OSO2CH3)6

Abstract The λ 6Si-silicate [Cs(18-crown-6)]2[Si(OSO2CH3)6] (1) was synthesized by treatment of Si2Cl6 with Cs[OSO2CH3] in the presence of 18-crown-6. Compound 1 is the first example of a λ 6Si-silicate with a methanesulfonate ligand. It was characterized by NMR spectroscopy and by single-crystal X-ray diffraction. The solid-state structure of 1 consists of discrete [Si(OSO2CH3)6]2– anions and two [Cs(18-crown-6)]+ cations (triclinic space group, P 1 ¯ $P\overline{1}$ , Z = 1).

Crystal structures of 9-[bis-(benzyl-sulfan-yl)meth-yl]anthracene and of cyclo-dodeca-kis-(μ2-phenyl-methane-thiol-ato-κ2 S:S)hexa-palladium(6 Pd-Pd)-anthracene-9,10-dione (1/1).

The first title compound, C29H24S2, L1, represents an example of an anthracene-based functionalized di-thio-ether, which may be useful as a potential chelating or terminal ligand for coordination chemistry. This di-thio-acetal L1 crystallizes in the monoclinic space group P21/c. The phenyl rings of the benzyl groups and that of the anthracene unit form dihedral angles of 49.21 (4) and 58.79 (5)° and the crystal structure displays short C-H⋯π contacts. Surprisingly, when attempting to coordinate L1 to [PdCl2(PhCN)2], instead of the targeted chelate complex [PdCl2(κ2-L1)], a cleavage reaction leads to the formation of the centrosymmetric hexa-nuclear cyclic cluster of composition [Pd6(μ2-SCH2Ph)12] Pd6, or [Pd6(C7H7S)12]·C14H8O2. This tiara-shaped hexa-mer crystallizing in the triclinic space group P consists of six approximately square planar Pd(II)S4 centers, which are inter-connected through twelve μ2-bridging benzyl thiol-ate groups. The Pd⋯Pd contacts range from 3.0892 (2) to 3.1609 (2) Å and can be considered as weakly bonding. The unit cell of Pd6 contains also a co-crystallized anthracene-9,10-dione mol-ecule.

Crystal structure and optical properties of a two-sited EuIII compound: an EuIII ion coordinated by two [EuIII(DOTA)]- complexes (DOTA is 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate).

The structure and solid-state luminescence properties of an EuIII compound with two different lanthanide sites, [Eu(μ-O)5(OH)(H2O)2][Eu(DOTA)(H2O)]2 (DOTA is 1,4,7,10-tetrazacyclododecane-1,4,7,10-tetraacetate, C16H24N4O8), were determined. The compound crystallizes in a laminar structure in the triclinic space group P-1, where the two sites are a free europium(III) ion and an [Eu(DOTA)(H2O)]- complex. The crystal structure was determined using complex data treatment due to nonmerohedral twinning. Experimental data sets were recorded with large redundancy and separated according to scattering domains in order to obtain a reliable structure. In the first site, the [Eu(DOTA)(H2O)]- complex was found to adopt a capped twisted square-antiprismatic (cTSAP) conformation, where a capping water molecule increased the coordination number of the europium(III) site to nine (CN = 9). In the second site, the europium(III) ion was found to be coordinated by two water molecules, one hydroxide group and five oxide groups from neighbouring [Eu(DOTA)(H2O)]- complexes. The coordination geometry of this site was found to be a compressed square antiprism (SAP) and the coordination number of the europium(III) ion was found to be eight (CN = 8). A large increase in the rate constant of luminescence was observed for EuIII in [Eu(DOTA)(H2O)]- in solid-state luminescence spectroscopy measurements compared to in solution, which led to investigations of single crystals in deuterated media to exclude additional effects of quenching. We conclude that the most probable cause of the decrease in the observed luminescence lifetimes is the high asymmetry of the coordination environment of [Eu(DOTA)(D2O)]- in the [Eu(μ-O)5(OD)(D2O)2][Eu(DOTA)(D2O)]2 crystals.

Crystal structure of new formamidinium triiodide jointly refined by single-crystal XRD, Raman scattering spectroscopy and DFT assessment of hydrogen-bond network features.

A novel triiodide phase of the formamidinium cation, CH5N2 +·I3 -, crystallizes in the triclinic space group P at a temperature of 110 K. The structure consists of two independent isolated triiodide ions located on inversion centers. The centrosymmetric character of I3 - was additionally confirmed by the observed pronounced peaks of symmetrical oscillations of I3 - at 115-116 cm-1 in Raman scattering spectra. An additional structural feature is that each terminal iodine atom is connected with three neighboring planar formamidinium cations by N-H⋯I hydrogen bonding with the N-H⋯I bond length varying from 2.81 to 3.08 Å, forming a deformed two-dimensional framework of hydrogen bonds. A Mulliken population analysis showed that the calculated charges of hydrogen atoms correlate well with hydrogen-bond lengths. The crystal studied was refined as a three-component twin with domain ratios of 0.631 (1):0.211 (1):0.158 (1).