High-symmetry embeddings of interpenetrating periodic nets. Essential rings and patterns of catenation.

Symmetrical embeddings are given for multiply intergrown sets of some commonly occurring nets such as dia (diamond), qtz (quartz), pcu (net of primitive cubic lattice) and srs (labyrinth net of the G minimal surface). Data are also given for all known pairs of nets which have edge-transitive self-dual tilings. Examples are given for symmetrical polycatenation of the 2-periodic nets sql (square lattice) and hcb (honeycomb).

Intermetallic crystal structures as foams. Beyond Frank-Kasper.

In many intermetallic structures, the atoms and bonds divide space into tilings by tetrahedra. The well-known Frank-Kasper phases are examples. The dual tilings divide space into a tiling by polyhedra that is topologically a foam.

Soft secondary building unit: dynamic bond rearrangement on multinuclear core of porous coordination polymers in gas media.

A new synthetic approach to prepare flexible porous coordination polymers (PCPs) by the use of soft secondary building units (SBUs) which can undergo multiple reversible metal-ligand bonds breaking is reported. We have prepared a zinc paddle-wheel-based two-fold interpenetrated PCP, {[Zn(2)(tp)(2)(L(2))]·2.5DMF·0.

Investigation of the GeO2-1,6-diaminohexane-water-pyridine-HF phase diagram leading to the discovery of two novel layered germanates with extra-large rings.

The systematic exploration of the phase diagram of the GeO(2)-1,6-diaminohexane-water-pyridine-HF system has allowed the identification of specific roles of the HF, H(2)O contents, and HF/H(2)O ratio in the formation of Ge(7)X(19) (Ge(7)), Ge(9)X(25-26) (Ge(9)), and Ge(10)X(28) (Ge(10)) clusters (X = O, OH, F). This work has led to the discovery of two novel structures with extra-large 18-membered rings accommodating 1,6-diaminohexane (DAH): SU-63, |1.5H(2)DAH|[Ge(7)O(14)X(3)]·2H(2)O, a layered germanate constructed from Ge(7) clusters with the Kagomé topology, and SU-64, |11H(2)DAH|[Ge(9)O(18)X(4)][Ge(7)O(14)X(3)](6)·16H(2)O, a germanate built of two-dimensional slabs containing both Ge(7) and Ge(9) clusters (X = OH or F).

Periodic molecular boxes in entangled enantiomorphic lcy nets.

In this contribution, we present a coordination framework built from a novel (Zn(4)O)(O(2)C)(6) metaprismatic unit showing the interpenetration of a pair of enantiomorphic lcy nets that exhibits commensurate sorption properties.

Open-framework germanate built from the hexagonal packing of rigid cylinders.

We present a novel open-framework oxide material constructed from Ge(10)(O,OH)(28) (Ge(10)) oxide clusters prepared via a nonsurfactant route. The material shows two distinct pore windows of 9.43 and 4.

A pillared-layer coordination polymer with a rotatable pillar acting as a molecular gate for guest molecules.

The design of pore properties utilizing flexible motifs and functional groups is of importance to obtain porous coordination polymers with desirable functions. We have prepared a 3D pillared-layer coordination polymer, {[Cd(2)(pzdc)(2)L(H(2)O)(2)].5(H(2)O).

The ITQ-37 mesoporous chiral zeolite.

The synthesis of crystalline molecular sieves with pore dimensions that fill the gap between microporous and mesoporous materials is a matter of fundamental and industrial interest. The preparation of zeolitic materials with extralarge pores and chiral frameworks would permit many new applications. Two important steps in this direction include the synthesis of ITQ-33, a stable zeolite with 18 x 10 x 10 ring windows, and the synthesis of SU-32, which has an intrinsically chiral zeolite structure and where each crystal exhibits only one handedness.

One-pot catalytic enantioselective domino nitro-michael/michael synthesis of cyclopentanes with four stereocenters.

A highly enantioselective organocatalytic one-pot synthesis of nitro-, formyl-, and ester-functionalized cyclopentanes with four stereocenters is presented. The cyclopentanes were formed as a predominant diasteroisomer and isolated in high yields with 97-99 % ee.

A zeolite family with chiral and achiral structures built from the same building layer.

Porosity and chirality are two of the most important properties for materials in the chemical and pharmaceutical industry. Inorganic microporous materials such as zeolites have been widely used in ion-exchange, selective sorption/separation and catalytic processes. The pore size and shape in zeolites play important roles for specific applications.

An open-framework silicogermanate with 26-ring channels built from seven-coordinated (Ge,Si)10(O,OH)28 clusters.

We report a new open-framework silicogermanate SU-61 containing 26-ring channels with a low framework density. It can be seen as a crystalline analogue to the mesoporous silica MCM-41. The structure is built from the assembly of (Ge,Si)10(O,OH)28 clusters.

Three-periodic nets and tilings: minimal nets.

The 15 3-periodic minimal nets of Beukemann & Klee [Z. Kristallogr. (1992), 201, 37-51] have been examined.