We have successfully synthesized NaX zeolite crystals with controlled sizes from 20 nm to 0.8 μm, using a novel organic-additive-free approach. We show that the NaX crystal size depends on the silicate source and hydrothermal crystallization conditions, especially crystallization temperature and agitation. The physical properties of NaX-nano (20−100 nm) were characterized by X-ray diffraction, high-resolution scanning electron microscopy, FT-IR spectroscopy, 29Si solid-state NMR spectroscopy, and N2 adsorption. The results were compared with those for micrometer-sized NaX crystals, NaX-μ. As expected, the external surface area of NaX-nano was found to be significantly enhanced compared with that of NaX-μ. Porosity analysis indicates that NaX-nano has a broad distribution of mesopores from 2 to 20 nm, associated with interparticle voids. Both FT-IR and 29Si solid-state NMR spectra revealed the presence of Q3 silicon atoms in NaX-nano. All four Q3 species were assigned in the 29Si NMR spectra.

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The synthesis and characterization of group 10 metal pincer complexes supported by a new bis(indolylphosphino)silyl ligand are described, including the synthesis of Ni, Pd, and Pt hydride species. Solution NMR and single-crystal X-ray data revealed that a significant amount of structural variability is possible for such hydride complexes, particularly in the case of Ni, where terminal Ni-H as well as complexes involving η 2 -SiH coordination are both accessible and may even coexist, in ratios dependent on factors such as the nature of additional coligands, including N 2 from the reaction atmosphere, as well as solvent and temperature. Nickel and palladium hydride complexes of this new ligand were found to exhibit divergent selectivity in the catalytic hydroboration of CO 2 with pinacolborane (HBPin). While the Pd catalyst exhibited moderate activity for CO 2 hydroboration to the formate level, the analogous Ni species exhibited unprecedented selectivity (97%) for hydroboration of CO 2 to the formaldehyde level to provide the bis(boryl)acetal PinBOCH 2 OBPin in high yield, under mild conditions. The HBPin-derived bis(boryl)acetal can be successfully isolated and utilized as a source of methylene for the formation of C−N and C−P bonds.

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Recognizing that catenation of carbon is principally responsible for the diversity and extent of organic chemistry, the "diagonal relationship" between carbon and phosphorus in the Periodic Table is often quoted [1,2] in the discussion of the numerous catenated polyphosphines [2][3][4][5][6] and polyphosphorus anions. [2][3][4][7][8][9][10][11][12] catena-Phosphorus cation systems are less well developed despite the classical chemistry of phosphonium salts, but the pioneering contributions of Schmidpeter and coworkers [13][14][15] and Schmutzler et al. [16] have highlighted new aspects of structure and bonding that prompt the establishment of a comprehensive polyphosphinophosphonium series. Our high-yielding and facile methods for the synthesis of the prototypical phosphinophosphonium 1, [17] diphosphinophosphonium 2, [18] and cyclotetraphosphinophosphonium 5 [18] cations have now been applied to the preparation of the first examples of cyclodiphosphinophosphonium 3 and cyclotriphosphinophosphonium 4 cations (Scheme 1). Isolation of these new frameworks is surprising in light of the exclusive formation of 5 over possible tetra-and hexaphosphorus derivatives with phenyl substituents at the phosphorus centers.[18] Derivatives of 3 and 4 provide representative frameworks that complete a series of the smallest cyclopolyphosphinophosphonium cations 3-5, and their characterization is pivotal in the systematic development of fundamental phosphorus chemistry.31 P NMR spectra of reaction mixtures containing (PtBu) 3 (6 a) with excess MeOTf show quantitative formation of [(PtBu) 3 Me][OTf] (3 a-OTf; Figure 1 a and Scheme 2 a). The spectrum can be approximated as an AMX [19] spin system and is consistent with the solid-state structure of 3 a-OTf (Figure 2 a), thus demonstrating stereoselective methylation of 6 a at either of the syn-configured centers to give a racemic Scheme 1. Prototypical catena-polyphosphinophosphonium cation frameworks. 31 P NMR spectra at 101.3 MHz: a) mixture of MeOTf (2 equiv) and (PtBu) 3 , which shows the approximate AMX pattern of 3 a-OTf; b) mixture of MeOTf (2 equiv) and (PCy) 4 , which shows the approximate A 2 MX pattern of 4 a-OTf; c) experimental (top) and simulated (inverted) AB 2 X pattern of pure 4 b-OTf.