Host perturbation in a β-hydroquinone clathrate studied by combined X-ray/neutron charge-density analysis: implications for molecular inclusion in supramolecular entities.

X-ray/neutron (X/N) diffraction data measured at very low temperature (15 K) in conjunction with ab initio theoretical calculations were used to model the crystal charge density (CD) of the host-guest complex of hydroquinone (HQ) and acetonitrile. Due to pseudosymmetry, information about the ordering of the acetonitrile molecules within the HQ cavities is present only in almost extinct, very weak diffraction data, which cannot be measured with sufficient accuracy even by using the brightest X-ray and neutron sources available, and the CD model of the guest molecule was ultimately based on theoretical calculations. On the other hand, the CD of the HQ host structure is well determined by the experimental data.

Experimental and theoretical charge densities of a zinc-containing coordination polymer, Zn(HCOO)2(H2O)2.

We present a combined experimental and theoretical charge density study of the coordination polymer Zn(HCOO)(2)(H(2)O)(2), which serves as a nonmagnetic reference for the isostructural magnetic compounds containing 3d transition metals. The charge density has been modeled using the multipole formalism against a high-resolution single-crystal X-ray diffraction data set collected at 100 K. The theoretical model is based on periodic density functional theory calculations in the experimental geometry.

Application of atomic Hirshfeld surface analysis to intermetallic systems: is Mn in cubic CeMnNi4 a thermoelectric rattler atom?

The Mn atom in the cubic polymorph of CeMnNi(4) appears to be located in an oversized cage-like structure, and anomalously large atomic displacement parameters (ADPs) for the Mn atom indicate that it is a potential "rattler" atom. Here, multitemperature synchrotron powder X-ray diffraction data measured between 110 and 900 K are used to estimate ADPs for the Mn "guest" atom and the "host" structure atoms in cubic CeMnNi(4). The ADPs are subsequently fitted with Debye and Einstein models, giving Θ(D) = 301(2) K for the "host" structure and Θ(E) = 165(2) K for the Mn atom.

Intermolecular interactions and electrostatic properties of the β-hydroquinone apohost: implications for supramolecular chemistry.

The crystal structure of the β-polymorph of hydroquinone (β-HQ), the apohost of a large family of clathrates, is reported with a specific focus on intermolecular interactions and the electrostatic nature of its cavity. Hirshfeld surface analysis reveals subtle close contacts between two interconnecting HQ networks, and the local packing and related close contacts were examined by breakdown of the fingerprint plot. An experimental multipole model containing anisotropic thermal parameters for hydrogen atoms has been successfully refined against 15(2) K single microcrystal synchrotron X-ray diffraction data.

Temperature-dependent crystal structure of the isopropanol clathrate of Dianin's compound.

The title compound undergoes two order-disorder transitions between 15 and 299 K, dictated by ordering of the guest molecules in the host cages, and resulting in three related crystal structures. We anticipate behaviour of this kind to be widespread, and speculate that the concept of "the crystal structure" for individual Dianin's clathrates may be elusive.

Synthesis, crystal structure, atomic Hirshfeld surfaces, and physical properties of hexagonal CeMnNi4.

The hexagonal polymorph of CeMnNi(4) has been synthesized using cold crucible, high-frequency induction melting with subsequent Czochralski crystal pulling. Single-crystal X-ray diffraction, multitemperature synchrotron powder X-ray diffraction (90 to 600 K), and neutron powder diffraction data have been measured to establish the detailed crystal structure and in particular the location of the Mn atoms. The neutron diffraction data provide sufficient scattering contrast between Mn and Ni to establish that the 2c site has an occupancy of 13% Mn atoms, while the 3g site has an occupancy of 25% Mn atoms.

Experimental and theoretical charge density study of chemical bonding in a Co dimer complex.

The charge density of Co2(CO)6(HC[triple bond]CC6H10OH) (1) in the crystalline state has been determined using multipolar refinement of single-crystal X-ray diffraction data collected (i) with a synchrotron source at very low temperatures (15 K) and (ii) using a conventional source with the crystal at intermediate temperature (100 K). The X-ray charge density model is augmented by complete active space and density functional theory calculations. Topological analyses of the different charge distributions show that the two Co atoms are not bonded to each other in the quantum theory of atoms in molecules (QTAIM) sense of the word.

Short strong hydrogen bonds in 2-acetyl-1,8-dihydroxy-3,6-dimethylnaphthalene: an outlier to current hydrogen bonding theory?

The environmental influence on the electronic character of two O-H...