Temperature-Tuned Variable Confined Space for Modulating Dipolar Polarization of a Disc-Shaped Ammonium Ion.

Free accessible confined space and loose interaction are crucial for most solid-state ionic motions. Here, by using a near-spherical anion and a disc-shaped ammonium as two distinct but rigid building blocks, we report a new ionic crystal, (HMIm)3[La(NO3)6] (HMIm = 1-methyl-1H-imidazol-3-ium), in which the different confined spaces of three (HMIm)+ ions are fine-tuned over a broad temperature range. This effect can be utilized to modulate the dipolar polarization across a wide temperature/frequency range. Additionally, small-scale substitution of (HMIm)+ by its isomer of almost identical shape/size affords molecular solid solutions, which can further tune the dipolar polarization by varying the doping ratio. It is revealed that the differences in dipole moment and hydrogen bond rather than that of shape/size lead to a distorted crystalline environment for these solid solutions. Overall, we provide an exceptional model for understanding and regulating the dipole motion of polar aromatic molecules/ions in a crystalline environment.

Poly[[{µ(3)-dihydrogen [(pyridin-4-yl-methyl-imino)-bis-(methyl-ene)]diphos-phon-ato-κO:O',N,O'':N'}copper(II)] dihydrate].

In the title polymer, {[Cu(C(8)H(12)N(2)O(6)P(2))]·2H(2)O}(n), the geometry of the five-coordinate Cu(II) ion can best be described as slightly distorted square-pyramidal formed by one N and two O atoms of an N(CH(2)PO(3)H)(2) group and one N atom from a pyridine ring. The elongated apex of the pyramid is occupied by one O atom from a third diphospho-nate ligand. The inter-connection of Cu(2+) ions by the diphospho-nate ligands results in the formation of a double-chain array along the b axis, in which the two sub-chains are inter-locked by pairs of PO(3) groups. The outside of each sub-chain is decorated by other PO(3) groups. These double chains are further assembled into a three-dimensional supra-molecular architecture via a large number of O-H⋯O hydrogen bonds between the phospho-nate groups and lattice water mol-ecules.

Tris(1,10-phenanthroline-kappa2N,N')cadmium(II) bis(perchlorate) 3.5-hydrate: a water chain stabilized by perchlorate anions.

The title compound, [Cd(C(12)H(8)N(2))(3)](ClO(4))(2).3.5H(2)O, contains a cross-shaped one-dimensional channel along the c axis which encapsulates an ordered water chain. This water chain features a centrosymmetric cyclic water hexamer unit with a chair-like conformation. Neighbouring hexamers are linked by bridging water molecules. The host perchlorate anions recognize and stabilize the guest water chain via three kinds of hydrogen-bond patterns, leading to the formation of a complex one-dimensional {[(H(2)O)(7)(ClO(4))(4)](4-)}(n) anionic chain. One perchlorate acts as a single hydrogen-bond acceptor dangling on the chain, the second perchlorate on the chain serves as a double hydrogen-bond acceptor for only one water molecule to form an R(2)(2)(6) ring, where both entities lie on a twofold axis, while the third perchlorate, which also lies on a twofold axis, accepts two hydrogen bonds from two equivalent water molecules and is involved in the construction of an R(6)(5)(14) ring.

1-(2-Bromo-2-de-oxy-ß-d-xylofuranos-yl)uracil.

In the title compound, C(9)H(11)BrN(2)O(5), the ribofuran-ose ring has a C2-exo, C3-endo twist configuration and is attached to the uracil unit via a ß-N(1)-glycosidic bond. The crystal structure is stabilized by two inter-molecular O-H⋯O inter-actions and one inter-molecular N-H⋯O inter-action.