Colloidal silica has been polymerized in the aqueous domain of lyotropic liquid crystal phases in ternary surfactant (Pluronic F127 or P123)-cosurfactant (butanol, pentanol, or hexanol)-water systems to create optically transparent mesostructured surfactant-cosurfactant-silica monoliths. The use of ternary systems enriches phase diagrams of aqueous surfactant systems, which in turn introduces more flexibility and diversity into the designed synthesis of mesoporous materials. Lyotropic surfactant liquid crystal phases are preserved throughout the inorganic polymerization and gelation processes and directly template the formation of inorganic mesophases. The cosurfactant chain length and the cosurfactant/surfactant mass ratio have been used to control the pore size. The large shrinkage of mesopores during calcination can be reduced with hydrothermal treatment prior to calcination. Highly ordered mesoporous silica samples with identical pore sizes, but very different wall thickness, can be prepared. The removal of surfactants and cosurfactants gives periodic hexagonal mesoporous silica with excellent thermal and hydrothermal stability.

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In contrast to the reactivity observed with the isoelectronic cyclopentadienyl salts, the reaction of CrCl 3 (THF) 3 with boratabenzene anions results in the formation of Cr(II) complexes. Thus, addition of Li(C 5 H 5 B-Me) to CrCl 3 (THF) 3 in THF gives (C 5 H 5 B-Me) 2 Cr (3). Similarly, Li(C 5 H 5 B-NMe 2 ) and CrCl 3 (THF) 3 yield (C 5 H 5 B-NMe 2 ) 2 Cr (4), while Li-(C 5 H 5 B-Ph) and CrCl 3 (THF) 3 provide (C 5 H 5 B-Ph) 2 Cr (5). Compounds 3-5 were characterized by single-crystal X-ray diffraction studies, and all possess typical sandwich structures. The reaction of borabenzene-ligand adducts with suitable Cr(III) starting materials provides boratabenzene-Cr(III) complexes. Addition of C 5 H 5 B-PMe 3 (Bb-PMe 3 ) to MeCrCl 2 (THF) 3 in benzene gives (C 5 H 5 B-Me)CrCl 2 (PMe 3 ) (6) in low yield. Treatment of MeCrCl 2 (THF) 3 with the pyridine adduct of borabenzene, C 5 H 5 B-NC 5 H 5 (Bb-Py), does not work effectively. The composition of one of the products from this reaction, the binuclear dimer [(C 5 H 5 B-Me)CrClMe] 2 (7), indicates Me/Cl redistribution processes. Treatment of CrCl 3 (THF) 3 with 3 equivalents MeMgBr in THF, followed by addition of Bb-Py gives (C 5 H 5 B-Me)CrMe 2 (Py) (8). Similarly, Ph 3 Cr(THF) 3 and Bb-Py afford (C 5 H 5 B-Ph)CrPh 2 (Py) (9). Compound 8 with the well-defined activators B(C 6 F 5 ) 3 and [Ph 3 C][B(C 6 F 5 ) 4 ] can polymerize ethylene with activities competitive with those of (C 5 H 5 B-Me)CrMe 2 (PMe 3 )/B(C 6 F 5 ) 3 (2/B(C 6 F 5 ) 3 ) and Cp*CrMe 2 (PMe 3 )/B(C 6 F 5 ) 3 . Methylaluminoxane (MAO) can also be used as an activator with the complexes containing a coordinated phosphine. The pyridine counterparts fail to give polymerization catalysts with MAO.

The syntheses, representative crystal structures, and some properties of a new family of microporous zincophosphate/arsenate materials, denoted M3Zn4O(XO4)3·nH2O (M = Li, Na, K, Rb, Cs, ...; X = P, As; n = ∼3.5−6), are reported. All these materials are based on a flexible, anionic Zn4O(XO4)3 network built up from vertex-linked tetrahedral ZnO4 and XO4 units. Four ZnO4 units share a vertex, resulting in novel OZn4 centers. The use of mixed four-coordinate anion types (XO4 3-, O2-) results in a number of interesting structural and stability properties. The M3Zn4O(XO4)3·nH2O network contains only pairs of 3-rings (a spiro-5 unit) and 8-rings, and no 4-rings or 6-rings: it encloses roughly spherical cavities connected by a three-dimensional network of 8-ring channels propagating in the orthogonal [100], [010], and [001] directions (cubic unit-cell axes). Extraframework cations and water molecules occupy these cavities and channels. These phases display typical “zeolitic” dehydration/rehydration and ion-exchange reactions with thermal stabilities up to 600 °C, the highest known for this type of open-framework Zn(P/As)O material. The included guest cation (Na, Rb, K, Li, ...) has a crucial effect on crystal structure, by ordering in and modifying the configuration of the intercavity 8-ring channels. The crystal structures of Rb3Zn4O(PO4)3·3.5H2O, K3Zn4O(AsO4)3·4H2O, and Na3Zn4O(PO4)3·6H2O are presented. Crystal data: Rb3Zn4O(PO4)3·3.5H2O, M r = 881.40, cubic, space group F4̄3c (No. 219), a = 15.3423(9) Å, V = 3611.4(6) Å3, Z = 8, R p = 5.12%, R wp = 6.78%, 27 parameters, 1874 data points (X-ray Rietveld refinement). K3Zn4O(AsO4)3·4H2O, M r = 883.63, cubic, space group F4̄3c (No. 219), a = 15.4638(2) Å, V = 3697.9(2) Å3, Z = 8, R p = 8.69%, R wp = 11.42%, 24 parameters, 2124 data points (X-ray Rietveld refinement). Na3Zn4O(PO4)3·6H2O, M r = 739.49, trigonal, space group R3c (No. 161), a = 10.7489(3) Å, α = 60.114(2)°, V = 880.4(4) Å3, Z = 2, R = 2.49%, R w = 2.61%, 180 parameters, 846 observed reflections with I > 3σ(I) (single-crystal data).