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The crystal structures of the title compounds, C19H19NO and C31H34N2O, were determined as part of an experiment in an undergraduate teaching laboratory that demonstrates the relationship between molecular structure and function. 1′,3′,3′-Trimethylspiro[chromene-2,2′-indoline] is both a photoswitch and thermochromic molecule. Students synthesized it and a bis-indoline adduct and compared the crystallographically determined structures to computed gas-phase models.

A new 30-center Ga(III)-oxy-hydroxide cation cluster was synthesized by hydrolysis of an aqueous GaCl3 solution near pH = 2.5 and crystallized using 2,6-napthalene disulfonate (NDS). The cluster has 30 metal centers and a nominal stoichiometry: [Ga30(μ4-O)12(μ3-O)4(μ3-OH)4(μ2-OH)42(H2O)16](2,6-NDS)6, where 2,6-NDS = 2,6-napthalene disulfonate This cluster augments the very small library of Group 13 clusters that have been isolated from aqueous solution and closely resembles one other Ga(III) cluster with 32 metal centers that had been isolated using curcurbit ligands. These clusters have uncommon linked Ga(O)4 centers and sets of both protonated and unprotonated μ3-oxo.

The structure of the title compound octakis{[4-(dimethylamino)pyridine](nitrosyl)[N,N′-(o-phenylene)bis(pyridine-2-carboxamidato)]manganese(II)} ethanol heptasolvate 3.5-hydrate, [Mn(C18H12N4O2)(C7H10N2)(NO)]8·7C2H5OH·3.5H2O, or 8[Mn(bpb)(DMAP)(NO)]·7EtOH·3.5H2O, is an unusual example of a structure with Z′ = 8. The tetradentate bpb ligand, together with the nitrosyl and dimethylaminopyridine ligands, gives rise to a distorted octahedral coordination environment for the Mn(II) ion. The average Mn—N(N=O) bond length is 1.631 (13) Å. The eight molecules in the asymmetric unit differ mainly in the rotation of the DMAP pyridine plane with respect to a reference plane of the Mn and three N atoms, one of which is the N atom of the NO group. The dihedral angles between the normals to these planes range from a minimum of 28.0 (2)° to a maximum of 64.2 (2)°. There are also some differences in O—H...O hydrogen bonding interactions. For example, of the sixteen C=O acceptors, there are seven different interactions with EtOH donors and two interactions with H2O donors. The crystal studied was found to be a two-component twin, with a 179.9° rotation about the real axis [−0.535, 0.004, 1.000]. Due to the presence of a superlattice and, consequently, the large number of weak reflections, the refinement utilized rigid solvate groups and isotropic displacement parameters for all except the Mn atoms. H atoms were not located for hydrate molecules.

The title compound, [Mn2O2(C10H24N4)2](C24H20B)2Cl·2CH3CN, is a mixed-valent MnIII/MnIV oxide-bridged manganese dimer with one chloride and two tetraphenylborate counter-anions. There are two non-coordinated molecules of acetonitrile in the formula unit. A center of inversion is present between the two metal atoms, and, consequently, there is no distinction between MnIII and MnIV metal centers. In the Mn2O2 core, the Mn—O distances are 1.817 (3) and 1.821 (3) Å. The cyclam ligand is in the cis configuration. The chloride counter-anion resides on a center of symmetry, whereas the tetraphenylborate counter-anion is in a general position. The cyclam ligand is hydrogen bonded to the acetonitrile as well as to the chloride anion. One of the phenyl rings of the anion and the acetonitrile solvent molecule are each disordered over two sets of sites.

The asymmetric unit of the title compound, [Pd(C12H12NO)2], consists of three crystallographically independent half-molecules. Each PdII atom lies on a center of inversion and is four-coordinated by two monoanionic forms of the aminoacrylaldehyde in a square-planar geometry. In the crystal, adjacent molecules are connected through C—H...π and C—H...O interactions into a three-dimensional polymeric structure.

The title compound, (C4H12N2)[Ce2(C4H4O4S)4(H2O)2]·3H2O, features a polymeric anion with a centrosymmetric Ce2O2 core and a Ce...Ce distance of 4.3625 (4) Å. The anions form ribbons {[Ce2(C4H4O4S)4(H2O)2]2−}n extending along [100]. The doubly protonated piperazinium cations reside on centers of inversion and link the polymeric ribbons via N—H...O hydrogen bonding. Each CeIII cation is ten-coordinated by an O2S donor set from two tridentate sulfanediyldiacetate (tda) ligands, one water molecule and three other tda O donors from adjacent {Ce(tda)2(H2O)} units in a distorted bicapped cubic environment. Additional O—H...O hydrogen bonding involving the coordinated and solvent water molecules is also present. H atoms of the crystal water molecules could not be located and were not included in the refinement.

The title compound, C13H10N+·C7H4NO4−·H2O or (acrH)+(pydcH)−·H2O, is a monohydrate of acridinium cations and a mono-deprotonated pyridine-2,6-dicarboxylic acid. The structure contains a range of non-covalent interactions, such as O—H...O, O—H...N and N—H...O hydrogen bonds, as well as π–π stacking [range of centroid–centroid distances = 3.4783 (5)–3.8059 (5) Å]. The N—H...O hydrogen bond between the donor acridinium cation and the carboxylate acceptor is particularly strong. The average separation between the π-stacked acridinium planes is 3.42 (3) Å.

The asymmetric unit of the title compound, 2C14H13N2+·2C4H5O6−·9H2O, contains two cations and two anions in addition to nine molecules of water. Each of the hydrogen tartrate anions is hydrogen bonded to itself by translation along [100] in a head-to-tail fashion via a short hydrogen bond with donor–acceptor distances of 2.473 (4) and 2.496 (4) Å. A large number of intermolecular O–H...O, N—H...O and C–H...O hydrogen-bonding interactions, as well as π–π stacking [centroid–centroid distances in the range 3.642 (3) to 3.866 (3) Å], play an important role in the crystal structure.

The centrosymmetric title cluster, hexaaquadi-μ3-carbonato-hexacyclamhexa-μ2-hydroxido-dodeca-μ2-oxido-hexamanganese(IV)hexamanganese(III) octachloride tetracosahydrate, [Mn12(CO3)2O12(OH)6(C10H24N4)6(H2O)6]Cl8·24H2O, has two μ3-CO3 groups that not only bridge octahedrally coordinated MnIII ions but also act as acceptors to two different kinds of hydrogen bonds. The carbonate anion is planar within experimental error and has an average C—O distance of 1.294 (4) Å. The crystal packing is stabilized by O—H...Cl, O—H...O, N—H...Cl and N—H...O hydrogen bonds. Two of the four independent chloride ions are disordered over five positions, and eight of the 12 independent water molecules are disordered over 21 positions.

The title salt, C8H20N+·C22H27O3S−, is a proton-transfer compound derived from the recently reported parent carboxylic acid [Alhadi et al. (2010). Acta Cryst. E66, o1787] by the addition of a second equivalent of di-n-butylamine, yielding the di-n-butylammonium carboxylate salt. The structure of the carboxylate anion resembles that of the parent carboxylic acid. The main difference lies in the position of the H atom in the 4-hydroxy group. In the anion the O—H bond is perpendicular, rather than parallel, to the benzyl ring. This position appears to facilitate hydrogen bonding to an O atom of the carboxylate group of a symmetry-related anion. In addition, there are three N—H...O hydrogen bonds. In contrast, the neutral species hydrogen bonds via a carboxylic acid dimer. The dihedral angle between the benzene rings in the anion is 79.19 (7)°.

In the title compound, C22H28O3S, the dihedral angle between the two aromatic rings is 80.56 (6)°. The hydroxy group is shielded by the two sterically hindered tert-butyl groups and therefore is not involved in any hydrogen bonding. The C—O—H fragment is coplanar with the aromatic ring, the dihedral angle between them being 7(5)°. In the crystal structure, pairs of molecules are hydrogen bonded across crystallographic centers of symmetry.

The title compound, (C13H11N2)2[Ni(C7H3NO4)2]·3H2O, consists of a mononuclear anionic complex, two 9-aminoacridinium cations and three uncoordinated water molecules. Two pyridine-2,6-dicarboxylate (pydc) ligands are bound to the NiII ion, giving an NiN2O4 bonded set. The coordination geometry around the NiII atom is distorted octahedral. There are two types of robust O—H...O hydrogen-bond synthons, namely R66(24) and R24(8), which link the complex anions and water molecules to each other. N—H...O hydrogen bonds connect the stacks of anions and cations in the structure. Other intermolecular interactions, including weak C—H...O hydrogen bonds, π–π [shortest centroid–centroid distance = 3.336 (7) Å] and C—O...π [O...centroid distance = 3.562 (10) Å] interactions, connect the various components.

The title structure, C12H9N2+·C4H5O6−·3H2O, shows that one of the protons of d-tartaric acid has been transferred to 1,10-phenanthroline. The d-hydrogen tartrate anions are joined together in a head-to-tail fashion via a short hydrogen bond with donor–acceptor distance of 2.4554 (12) Å, unsymmetrical O—H distances of 1.01 (4) Å and 1.45 (4) Å, and a 174 (4)° O—H—O bond angle. The phenanthrolinium rings are π-stacked with an average separation of 3.58 (11) Å. The structural report corrects a previous report in the literature [Wang et al. (2006). Acta Cryst. E62, o2508–o2509] of the isostructural l-hydrogen tartrate enantiomer in which the proton transfer and short hydrogen bond were missed.

The title compound, {[BaPt(CN)4(C12H26N2O4)]·0.5H2O}n, is a two-dimensional coordination polymer in which the sheets are oriented approximately parallel to the (overline{1}01) set of crystal planes. In the crystal structure, disordered water molecules (half occupancy) connect the sheets into a three-dimensional network via intermolecular O—H...O hydrogen bonds. An N—H...N interaction is also present. The shortest Pt...Pt contacts are 7.5969 (4) Å by an inversion relationship and 7.6781 (4) Å by translation along the a axis.

The reaction of copper(II) nitrate hexahydrate with pyridine-2,6-dicarboxylic acid (pydcH2) and 2,4,6-triamino-1,3,5-triazine (melamine) in aqueous solution in a 1:2:2 molar ratio gave the title compound, (H5O2)(C3H7N6)3[Cu(C7H3NO4)2]2·C7H5NO4·6H2O. The hydroxonium hydrate (H5O2)+, also known as the Zundel cation, resides on a twofold rotation axis. The O—H distance is 1.274 (14) Å, the O...O distance is 2.518 (5) Å, and the O—H—O angle is 162 (8)°. One of the melamine H+ cations, the uncoordinated pydcH2, and two water molecules also reside on crystallographic twofold axes. The CuII atom has a tetragonally distorted octahedral coordination environment. The structure features extensive hydrogen bonding, with 21 distinct interactions. There is also a centrosymmetric C=O...π interaction with an O...centroid distance of 3.288 (3) Å. The structure is similar to a mixed-valence manganese(II/III) structure but shows interesting differences in the metal-atom coordination. One of the water molecules is equally disordered with respect to a twofold axis.

The title compound, [Co(C21H22NO)2], crystallizes with two molecules in the asymmetric unit. The coordination environments of the two CoII ions are distorted tetrahedral. The primary structural difference between the two independent complex molecules lies in the orientations of their adamantyl groups.

The title compound, (C4H8N3O)[Cr(C7H3NO4)2]·C7H5NO4·6H2O, was obtained by the reaction of Cr(NO3)3·9H2O with pyridine-2,6-dicarboxylic acid (pydcH2) and creatinine (creat) in aqueous solution (molar ratio 1:2:2). The cation is a protonated creatinine (creatH+) while the anion is a bis-pydc2− CrIII complex. The CrIII is coordinated by four oxygen and two nitrogen atoms of two (pydc)2– groups and has a disorted octahedral coordination environment. The structure also contains a neutral molecule of pydcH2 that is hydrogen bonded to the creatH+ and six molecules of water. Extensive intermolecular interactions, including seventeen classical hydrogen bonds, two weak C—H...O bonds, and C—O...π stacking interactions, with O...centroid distances of 3.211 (13) and 3.300 (12) Å, connect the various components in the crystal structure.

Crystallographic and luminescence studies on salts of the two-coordinate carbene cation, [Au{C(NHCH3)(NHCH2CH2OH)}2]+, demonstrate the ability of the cation to exist in three different states of aggregation. In colorless, non-luminescent [Au{C(NHCH3)(NHCH2CH2OH)}2]Cl the cation crystallizes as a monomer with the nearest gold(i) center 6.7890(11) Å away. Colorless, luminescent [Au{C(NHCH3)(NHCH2CH2OH)}2]AsF6 forms dimers with an Au⋯Au separation of 3.1288(4) Å. These dimers form weakly associated extended chains of cations with additional Au⋯Au separations of 3.6625(5) Å. [Au{C(NHCH3)(NHCH2CH2OH)}2]PF6 is isostructural. Yellow, luminescent [Au{C(NHCH3)(NHCH2CH2OH)}2]3(AsF6)2Cl·0.5(H2O)2 and [Au{C(NHCH3)(NHCH2CH2OH)}2]3(PF6)2Cl·0.5(H2O)2 form trimers that further aggregate into extended chains with rather short Au⋯Au separations of 3.1301(14) Å, 3.1569(14) Å and 3.1415(14) Å. Absorption, emission and excitation spectra are reported for these salts. The excitation and emission results from the interactions between the gold centers and involves transitions between the filled dz2 band and the empty pz bands with the z axis pointing along the chain of cations. [ABSTRACT FROM AUTHOR]

Addition of two equivalents of CuCl to deprotonated bis-(2-(2-pyridyl)ethyl)-2-(N-toluenesulfonylamino)ethylamine (PETAEA) and its derivatives yielded new types of dinuclear Cu(i) complexes, Cu(µ-PETAEA)CuCl, Cu(µ-PEMAEA)CuCl, and Cu(µ-PENAEA)CuCl (PEMAEA is the 4-methoxyphenyl derivative of PETAEA and PENAEA is the 4-nitrophenyl derivative), exhibiting a four coordinate N4Cu center, a two coordinate NCuCl center, and a metal–metal distance within the range of 2.6572(8) to 2.6903(3) Å. Analysis of the covalent radii for four coordinate and two coordinate copper(i), the acute copper–nitrogen–copper angles, and density functional theory (DFT) calculations suggest a weak attraction between the two copper atoms. The complexes apparently formed in a two-step process with the formation of the tetracoordinate mononuclear complex preceding the coordination of a second equivalent of CuCl to the lone pair of the sulfonamidate ligand. [ABSTRACT FROM AUTHOR]

Cocrystallization of Co2(CO)8with C60traps the cobalt carbonyl molecule as the D3disomer that otherwise is not available for crystallographic analysis. [ABSTRACT FROM AUTHOR]