Three new 1H-indole derivatives, namely, 2-(bromomethyl)-3-methyl-1-(phenylsulfonyl)-1H-indole, C16H14BrNO2S, (I), 2-[(E)-2-(2-bromo-5-methoxyphenyl)ethenyl]-3-methyl-1-(phenylsulfonyl)-1H-indole, C24H20BrNO3S, (II), and 2-[(E)-2-(2-bromophenyl)ethenyl]-3-methyl-1-(phenylsulfonyl)-1H-indole, C23H18BrNO2S, (III), exhibit nearly orthogonal orientations of their indole ring systems and sulfonyl-bound phenyl rings. Such conformations are favourable for intermolecular bonding involving sets of slipped π–π interactions between the indole systems and mutual C—H...π hydrogen bonds, with the generation of two-dimensional monoperiodic patterns. The latter are found in all three structures, in the form of supramolecular columns with every pair of successive molecules related by inversion. The crystal packing of the compounds is additionally stabilized by weaker slipped π–π interactions between the outer phenyl rings (in II and III) and by weak C—H...O, C—H...Br and C—H...π hydrogen bonds. The structural significance of the different kinds of interactions agree with the results of a Hirshfeld surface analysis and the calculated interaction energies. In particular, the largest interaction energies (up to −60.8 kJ mol−1) are associated with pairing of antiparallel indole systems, while the energetics of weak hydrogen bonds and phenyl π–π interactions are comparable and account for 13–34 kJ mol−1.

The title molecule, C18H26O4, consists of two symmetrical halves related by the inversion centre at the mid-point of the central –C—C– bond. The hexene ring adopts an envelope conformation. In the crystal, the molecules are connected into dimers by C—H...O hydrogen bonds with R 2 2(8) ring motifs, forming zigzag ribbons along the b-axis direction. According to a Hirshfeld surface analysis, H...H (68.2%) and O...H/H...O (25.9%) interactions are the most significant contributors to the crystal packing. The contribution of some disordered solvent to the scattering was removed using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18] in PLATON. The solvent contribution was not included in the reported molecular weight and density.

In the title compound, C31H24N4O2, the dihydroquinoxaline units are both essentially planar with the dihedral angle between their mean planes being 64.82 (4)°. The attached phenyl rings differ significantly in their rotational orientations with respect to the dihydroquinoxaline planes. In the crystal, one set of C—H...O hydrogen bonds form chains along the b-axis direction, which are connected in pairs by a second set of C—H...O hydrogen bonds. Two sets of π-stacking interactions and C—H...π(ring) interactions join the double chains into the final three-dimensional structure.

The complex [Pt(C9H6NO)Cl(C2H4)], (I), was synthesized and structurally characterized by ESI mass spectrometry, IR, NMR spectroscopy, DFT calculations and X-ray diffraction. The results showed that the deprotonated 8-hy-droxy-quinoline (C9H6NO) coordinates with the PtII atom via the N and O atoms while the ethyl-ene coordinates in the η2 manner and in the trans position compared to the coordinating N atom. The crystal packing is characterized by C-H⋯O, C-H⋯π, Cl⋯π and Pt⋯π inter-actions. Complex (I) showed high selective activity against Lu-1 and Hep-G2 cell lines with IC50 values of 0.8 and 0.4 µM, respectively, 54 and 33-fold more active than cisplatin. In particular, complex (I) is about 10 times less toxic to normal cells (HEK-293) than cancer cells Lu-1 and Hep-G2. Furthermore, the reaction of complex (I) with guanine at the N7 position was proposed and investigated using the DFT method. The results indicated that replacement of the ethyl-ene ligand with guanine is thermodynamically more favorable than the Cl ligand and that the reaction occurs via two consecutive steps, namely the replacement of ethyl-ene with H2O and the water with the guanine mol-ecule.

In the title compound, C20H17BrO5S, mol-ecules are connected by inter-molecular C-H⋯S hydrogen bonds with R 2 2(10) ring motifs, forming ribbons along the b-axis direction. C-H⋯π inter-actions consolidate the ribbon structure while van der Waals forces between the ribbons ensure the cohesion of the crystal structure. According to a Hirshfeld surface analysis, H⋯H (40.5%), O⋯H/H⋯O (27.0%), C⋯H/H⋯C (13.9%) and Br⋯H/H⋯Br (11.7%) inter-actions are the most significant contributors to the crystal packing. The thio-phene ring and its adjacent di-carboxyl-ate group and the three adjacent carbon atoms of the central hexene ring to which they are attached were refined as disordered over two sets of sites having occupancies of 0.8378 (15) and 0.1622 (15). The thio-phene group is disordered by a rotation of 180° around one bond.

Lanthanide-containing materials are of interest in the field of crystal engineering because of their unique properties and distinct structure types. In this context, a new samarium–sodium heterometallic coordination polymer, poly[tetrakis(μ2-2-formyl-6-methoxyphenolato)samarium(III)sodium(I)], {[SmNa(C8H7O3)4]·solvent} n (Sm-1), was synthesized and crystallized via slow evaporation from a mixture of ethanol and acetonitrile. The compound features alternating SmIII and NaI ions, which are linked by ortho-vanillin (o-vanillin) ligands to form a mono-periodic chain-like coordination polymer. The chains propagate along the [001] direction. Residual electron density of disordered solvent molecules in the void space could not be reasonably modeled, thus the SQUEEZE function was applied. The structural, vibrational, and optical properties are reported.

Syntheses of the acyclic amidinium salts, morpholino-formamidinium hexa-fluorido-phosphate [OC4H8N-CH=NH2]PF6 or C5H11N2O+·PF6 -, 1, and pyrrolidinoformamidinium hexa-fluorido-phosphate [C4H8N-CH= NH2]PF6 or C5H11N2 +·PF6 -, 2, were carried out by heating either morpholine or pyrrolidine with triethyl orthoformate and ammonium hexa-fluorido-phosphate. Crystals of 1 obtained directly from the reaction mixture contain one cation and one anion in the asymmetric unit. The structure involves cations linked in chains parallel to the b axis by N-H⋯O hydrogen bonds in space group Pbca, with glide-related chains pointing in opposite directions. Crystals of 1 obtained by recrystallization from ethanol, however, showed a similar unit cell and the same basic structure, but unexpectedly, there was positional disorder [occupancy ratio 0.639 (4):0.361 (4)] in one of the cation chains, which lowered the crystal symmetry to the non-centrosymmetric space group Pca21, with two cations and anions in the asymmetric unit. In the pyrrolidino compound, 2, cations and anions are ordered and are stacked separately, with zigzag N-H⋯F hydrogen-bonding between stacks, forming ribbons parallel to (101), extended along the b-axis direction. Slight differences in the delocalized C=N distances between the two cations may reflect the inductive effect of the oxygen atom in the morpholino compound.

The title complex, [ZnCl(C12H15N3O2)2][ZnCl3(CH3CN)], was synthesized and its structure was fully characterized through single-crystal X-ray diffraction analysis. The complex crystallizes in the ortho-rhom-bic system, space group Pbca (61), with a central zinc atom coordinating one chlorine atom and two pyrrolidinyl-4-meth-oxy-phenyl azoformamide ligands in a bidentate manner, utilizing both the nitro-gen and oxygen atoms in a 1,3-heterodiene (N=N-C=O) motif for coordinative bonding, yielding an overall positively (+1) charged complex. The complex is accompanied by a [(CH3CN)ZnCl3]- counter-ion. The crystal data show that the harder oxygen atoms in the heterodiene zinc chelate form bonding inter-actions with distances of 2.002 (3) and 2.012 (3) Å, while nitro-gen atoms are coordinated by the central zinc cation with bond lengths of 2.207 (3) and 2.211 (3) Å. To gain further insight into the inter-molecular inter-actions within the crystal, Hirshfeld surface analysis was performed, along with the calculation of two-dimensional fingerprint plots. This analysis revealed that H⋯H (39.9%), Cl⋯H/H⋯Cl (28.2%) and C⋯H/H⋯C (7.2%) inter-actions are dominant. This unique crystal structure sheds light on arrangement and bonding inter-actions with azo-formamide ligands, and their unique qualities over similar semicarbazone and azo-thio-formamide structures.

The synthetic availability of mol-ecular water oxidation catalysts containing high-valent ions of 3d metals in the active site is a prerequisite to enabling photo- and electrochemical water splitting on a large scale. Herein, the synthesis and crystal structure of di-ammonium {μ-1,3,4,7,8,10,12,13,16,17,19,22-dodeca-aza-tetra-cyclo-[8.8.4.13,17.18,12]tetra-cosane-5,6,14,15,20,21-hexa-onato}ferrate(IV) acetic acid tris-olvate, (NH4)2[FeIV(C12H12N12O6)]·3CH3COOH or (NH4)2[FeIV(L-6H)]·3CH3COOH is reported. The FeIV ion is encapsulated by the macropolycyclic ligand, which can be described as a dodeca-aza-quadricyclic cage with two capping tri-aza-cyclo-hexane fragments making three five- and six six-membered alternating chelate rings with the central FeIV ion. The local coord-ination environment of FeIV is formed by six deprotonated hydrazide nitro-gen atoms, which stabilize the unusual oxidation state. The FeIV ion lies on a twofold rotation axis (multiplicity 4, Wyckoff letter e) of the space group C2/c. Its coordination geometry is inter-mediate between a trigonal prism (distortion angle φ = 0°) and an anti-prism (φ = 60°) with φ = 31.1°. The Fe-N bond lengths lie in the range 1.9376 (13)-1.9617 (13) Å, as expected for tetra-valent iron. Structure analysis revealed that three acetic acid mol-ecules additionally co-crystallize per one iron(IV) complex, and one of them is positionally disordered over four positions. In the crystal structure, the ammonium cations, complex dianions and acetic acid mol-ecules are inter-connected by an intricate system of hydrogen bonds, mainly via the oxamide oxygen atoms acting as acceptors.

The asymmetric unit of the title compound, μ-biphenyl-4,4'-di-sulfonato-bis-(aqua-lithium), [Li2(C12H8O6S2)(H2O)2] or Li2[Bph(SO3)2](H2O)2, consists of an Li ion, half of the diphenyl-4,4'-di-sulfonate [Bph(SO3 -)2] ligand, and a water mol-ecule. The Li ion exhibits a four-coordinate tetra-hedral geometry with three oxygen atoms of the Bph(SO3 -)2 ligands and a water mol-ecule. The tetra-hedral LiO4 units, which are inter-connected by biphenyl moieties, form a layer structure parallel to (100). These layers are further connected by hydrogen-bonding inter-actions to yield a three-dimensional network.