Bond length of perchlorate at different temperatures: X-ray and neutron comparison.

The averages (average deviations from the mean are given in square brackets) of uncorrected Cl-O bond distances in a perchlorate anion from an X-ray diffraction analysis of (N-{2-[bis(pyridin-2-ylmethyl)amino]ethyl}pyridine-2-carboxamidato)(nitric oxide)manganese perchlorate acetonitrile disolvate, [Mn(C20H20N5O)(NO)]ClO4·2CH3CN or [Mn(PaPy3)(NO)]ClO4·2CH3CN, decrease from 1.447 [4] Å at 10 K to 1.428 [4] Å at 170 K. The 10 K value is close to the neutron value (1.441 [1] Å) at 18 K. Comparisons are made with a second X-ray study at 30 K [1.444 (8) Å] and to libration-corrected, density functional theory (DFT), and Cambridge Structural Database (CSD) values

Bis(9-amino-acridinium) bis-(pyridine-2,6-dicarboxyl-ato-κO,N,O)nickelate(II) trihydrate.

The title compound, (C(13)H(11)N(2))(2)[Ni(C(7)H(3)NO(4))(2)]·3H(2)O, consists of a mononuclear anionic complex, two 9-amino-acridinium cations and three uncoordinated water mol-ecules. Two pyridine-2,6-dicarboxyl-ate (pydc) ligands are bound to the Ni(II) ion, giving an NiN(2)O(4) bonded set. The coordination geometry around the Ni(II) atom is distorted octa-hedral. There are two types of robust O-H⋯O hydrogen-bond synthons, namely R(6) (6)(24) and R(2) (4)(8), which link the complex anions and water mol-ecules to each other. N-H⋯O hydrogen bonds connect the stacks of anions and cations in the structure. Other inter-molecular inter-actions, 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] inter-actions, connect the various components

A temperature-dependent phase transformation of (E)-2-[(4-chloro-phen-yl)imino]-ace-naphthylen-1-one.

The crystal structure determination based on 90 K data of the title imine ligand, C18H10ClNO, revealed non-merohedral twinning with three twin domains. In our experience, this is an indication of an ordering phase transition. Consequently, the structure was redetermined with higher temperature data, and a reversible phase transition was discovered. The higher temperature phase is indeed an ordered structure. At the higher temperature, the 4-chloro-phenyl group has rotated by ca 7° into a crystallographic mirror plane. Warming the crystal from 90 K to 250 K changes the space group from triclinic P-1, to monoclinic P21/m. Diverse non-classical inter-actions are present in the crystal packing, and these are described for the phase change reported in this work. The crystal structure of the title imine ligand, measured at 100 K, has been reported on previously [Kovach et al. (2011 ▸). J. Mol. Struct.992, 33-38]

Di-μ-oxido-bis-[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κN,N',N'',N''')dimangan-ese(III,IV)] bis-(tetra-phenyl-borate) chloride acetonitrile disolvate.

The title compound, [Mn(2)O(2)(C(10)H(24)N(4))(2)](C(24)H(20)B)(2)Cl·2CH(3)CN, is a mixed-valent Mn(III)/Mn(IV) oxide-bridged mangan-ese dimer with one chloride and two tetra-phenyl-borate counter-anions. There are two non-coordinated mol-ecules of acetonitrile in the formula unit. A center of inversion is present between the two metal atoms, and, consequently, there is no distinction between Mn(III) and Mn(IV) metal centers. In the Mn(2)O(2) 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 tetra-phenyl-borate 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

Bis(2,9-dimethyl-1,10-phenanthrolin-1-ium) hydrogen (S,S)-tartrate nona­hydrate

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

Monomers, dimers, and trimers of [Au(CN)2]− in a Ba(diaza-18-crown-6)2+ coordination polymer

The structure of the title compound, poly[triaquatetra-μ-cyanido-tetracyanidobis­(1,4,10,13-tetra­oxa-7,16-diaza­cyclo­octa­deca­ne)di­barium(II)tetra­gold(I)], [Au4Ba2(CN)8(C12H26N2O4)2(H2O)3]n, displays O—H⋯N hydrogen bonding between water molecules and cyano ligands and an unusual pattern of aurophilic inter­actions that yields a monomer, dimer, and trimer of [Au(CN)2]− within the same crystal structure. In two of the five Au positions, the atom resides on a center of inversion. The overall arrangement is that of a coordination polymer assisted by aurophilic and hydrogen-bonded inter­actions

Bis[3,3-dimethyl-2-(2-oxoethyl­idene)indolinyl-κ2 N,O]palladium(II)

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

Poly[[tri-μ-cyanido-cyanido(1,4,10,13-tetra­oxa-7,16-diaza­cyclo­octa­deca­ne)barium(II)platinum(II)] hemihydrate]

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 (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