A remarkable solvent effect on the nuclearity of neutral titanium(IV)-based helicate assemblies.

The spontaneous self-assembly of a neutral circular trinuclear Ti(IV) -based helicate is described through the reaction of titanium(IV) isopropoxide with a rationally designed tetraphenolic ligand. The trimeric ring helicate was obtained after diffusion of n-pentane into a solution with dichloromethane. The circular helicate has been characterized by using single-crystal X-ray diffraction study, (13) C CP-MAS NMR and (1) H NMR DOSY solution spectroscopic, and positive electrospray ionization mass-spectrometric analysis.

A guest-induced reversible switching of a self-assembled H-bonded supramolecular framework.

A new class of organic crystalline 2,2'-biphenol-based H-bonded material displaying 1D-channels encapsulating solvent molecules is described. A reversible guest-induced crystal-to-crystal conversion between the solvated H-bonded phase and a compact H-bonded non-solvated phase was observed. The energy competition between intramolecular H-bonds formation and solvation of organic pores has been characterized using PACHA calculations.

Spontaneous symmetry breaking during self-assembly of a double stranded biphenolate-based Ti(IV)-helicate.

A binuclear Ti(IV)-based helicate synthesized from a symmetric tetrahydroxyheptaphenylene strand was self-assembled in solution and shown to undergo a spontaneous head-to-tail differentiation according to single-crystal X-ray diffraction.

Synthesis and characterization of a monomeric octahedral C2-symmetric titanium complex bearing two 3,3'-diphenyl-2,2'-biphenol ligands.

The 3,3'-diphenyl-2,2'-biphenol (dpbpolH(2)) ligand is shown to react with Ti(OPr(i))(4) in a 2:1 ratio to yield a novel C(2)-symmetric mononuclear octahedral Ti(IV) bis-biphenolate complex, cis-Ti(dpbpol)(2)(HOPr(i))(2).

Order-disorder in the super-sodalite Zn3Al6(PO4)12, 4tren, 17H2O (MIL-74): a combined XRD-NMR assessment.

A new mixed zinc-aluminum phosphate Zn(3)Al(6)(PO(4))(12), 4tren, 17H(2)O (MIL-74) has been hydrothermally synthesized with the tris(2-aminoethyl)amine (tren) as a structure-directing agent (453 K, 36 h, autogenous pressure). The solid was characterized by a nonclassical method combining single-crystal X-ray diffraction and several solid-state NMR experiments, RFDR, C7 double quantum ((31)P), and 3QMAS ((27)Al). Its crystal structure is cubic, a = 16.

A rationale for the large breathing of the porous aluminum terephthalate (MIL-53) upon hydration.

Aluminum 1,4-benzenedicarboxylate Al(OH)[O(2)C-C(6)H(4)-CO(2)]. [HO(2)C-C(6)H(4)-CO(2)H](0.70) or MIL-53 as (Al) has been hydrothermally synthesized by heating a mixture of aluminum nitrate, 1,4-benzenedicarboxylic acid, and water, for three days at 220 degrees C.

MIL-50, an open-framework GaPO with a periodic pattern of small water ponds and dry rubidium atoms: a combined XRD, NMR, and computational study.

A new fluorinated gallium phosphate, MIL-50, has been synthesized under mild hydrothermal conditions using 1,6-diaminohexane. The chemical formula of MIL-50 is Rb(2)Ga(9)(PO(4))(8)(HPO(4))(OH)F(6).2N(2)C(6)H(18).

Optimizing STMAS.

The 2D satellite transition magic angle spinning (STMAS) experiment generates efficiently high-resolution isotropic NMR spectra of half-integer quadrupolar nuclei. The experiment involves excitation and coherence transfer of satellite transitions into the central transition. It requires efficient refocusing of satellite transitions and sample spinning at a very accurate magic angle to cancel the first-order quadrupolar interaction effect.