Yihua Xu

Bio: Yihua Xu is an academic researcher from Jilin University. The author has contributed to research in topics: Hydrothermal synthesis & Infrared spectroscopy. The author has an hindex of 7, co-authored 11 publications receiving 164 citations.

Structures and Templating Effect in the Formation of 2D Layered Aluminophosphates with Al3P4O163- Stoichiometry

Abstract: The structural features of a family of layered aluminophosphates with Al3P4O163- stoichiometry (denoted L-n) have been discussed. Their 2D sheets are stabilized by protonated organic amines through H-bonding interactions with certain regularity. The templating ability of various organic amines for the experimental inorganic layers is investigated in terms of the energies of the host−template interactions. Some experimental phenomena, such as the packing sequence of the inorganic layers and the co-templating role of two types of templates on the formation of some structures, can be explained by energy calculation results. Some organic templates that can potentially direct the formation of a given host can be predicted. This further assists in the rational synthesis of 2D layered compounds with specific structures.

Rational Design of Two-Dimensional Layered Aluminophosphates with [Al3P4O16]3- Stoichiometry

Abstract: Topological analysis elucidates some general features of two dimensional (2D) 3.4-connected nets of aluminophosphates with Al3P4O163- stoichiometry. It proves that four-membered rings (4MRs) are essential for the construction of their networks. The distinct 2D sheets of Al3P4O163- layers, including both known and hypothetical nets, are systematically generated by computer. Calculation results show that a large number of 2D nets are energetically feasible compared to the known 2D nets. This suggests that they are likely to be synthesized under certain conditions. The secondary building units (SBUs) constructing the 2D networks of Al3P4O163- layers are commonly found as capped 6MRs (SBU1), double-diamond rings (SBU2), branched edge-sharing double 4MRs (SBU3), and double intergrown-capped 6MRs (SBU4). Some typically hypothetical 2D nets including novel 4.6, 4.6.8, 4.6.8.12, 4.8, and 4.6.10 nets, which have lower energies, are described in this paper. The calculated bond lengths and bond angles are in agreeme...

Synthesis and characterization of a novel boron-containing aluminium basic chloride

Abstract: A novel boron-containing aluminium basic chloride [B-C(1)] has been hydrothermally synthesized in the system B2O3–Al2O3–MxO–H2O (M = Li, Na, K, Mg, Ca, Ba; x= 1 or 2) and characterized by X-ray diffraction (XRD), inductive coupled plasma-analysis (ICP), scanning electron microscopy (SEM), infrared spectroscopy (IR), magicangle spinning nuclear magnetic resonance spectroscopy (MASNMR) and thermal analysis techniques There are significant effects due to pH, temperature and type of ion in the reaction mixture on the crystallization products Chemical analysis shows that B-C(1) has a composition of B015Al985O9(OH)10Cl2 The crystal is indexable on an orthorhombic unit cell with a= 1927 A, b= 1480 A, and c= 855 A B-C(1) may undergo thermal transformation sequences involving γ-, δ-, θ-, and α-aluminas at different temperatures IR spectroscopy and temperature-programmed desorption of NH3(NH3-TPD) reveals that there are predominantly Lewis acid sites of medium strength on the surface of B-C(1) It can be shown that B-C(1) is an excellent catalyst for the selective synthesis of but-2-ene from ethanol

Rich structure chemistry in the aluminophosphate family.

Abstract: This Account describes a family of aluminophosphates ranging from neutral open-frameworks to anionic frameworks with fascinating structural architectures. In contrast to aluminosilicate zeolites, these aluminophosphates exhibit wealthy structural features, including extra-large micropores, mixed bonding, different structural dimensionalities, rich compositional diversities, and various stacking sequences of their 2-D sheets. The low-dimensional networks, acting as building units, can be assembled to 3-D open-frameworks via transition metal cations through a building-up process. New stoichiometries and hypothetical structural topologies can be predicted and enumerated. Computational and combinatorial approaches will greatly help to access the range of the diverse structures.

Insight into the construction of open-framework aluminophosphates

Abstract: Over the past twenty five years, a class of open-framework aluminophosphates, denoted AlPOs, has been prepared with neutral zeolitic frameworks and anionic frameworks showing wonderfully complex structural and compositional diversity. An insight into the construction of open-framework AlPOs revealing their general structural features and topological chemistry is provided in this tutorial review, and the role of templating and the designed construction and synthesis of AlPOs are discussed.

Structural variation from 1D to 3D: effects of ligands and solvents on the construction of lead(II)-organic coordination polymers.

Abstract: A series of Pb(II) coordination polymers [Pb(ndc)(dpp)] (1), [Pb(ndc)(ptcp)].0.5 H2O (2), [Pb(ndc)(dppz)] (3), [Pb(ndc)(tcpn)(2)] (4), [Pb2(ndc)2(tcpp)] (5), [Pb(Hndc)2].H2O (6), [Pb(ndc)(dma)] (7), [Pb(bdc)(dma)] (8), [Pb(trans-chdc)(H2O)] (9), and [Pb2(cis-chdc)2].NH(CH3)2 (10), where ndc=1,4-naphthalenedicarboxylate, dpp=4,7-diphenyl-1,10-phenanthroline, ptcp=2-phenyl-1H-1,3,7,8-tetraazacyclopenta[l]phenanthrene, dppz=dipyrido[3,2-a:2',3'-c]phenazine, tcpn=2-(1H-1,3,7,8-tetraazacyclopenta[l]phenanthren-2-yl)naphthol, tcpp=4-(1H-1,3,7,8-tetraazacyclopenta[l]phenanthren-2-yl)phenol, dma=N,N-dimethylacetamide, bdc=1,4-benzenedicarboxylate, and chdc=1,4-cyclohexanedicarboxylate, have been synthesized from a hydrothermal or solvothermal reaction system by varying the ligands or the solvents. Compounds 1-5 crystallize with an N-donor chelating ligand and an aromatic dicarboxylate linker. Compounds 1-4 are 1D polymers with different pi-pi stacking interactions, whereas compound 5 consists of 2D layers. The structures of compounds 7, 8, and 10 are 3D frameworks formed by connection of the Pb(II) centers by organic acid ligands. Compound 7 is chiral although the ndc ligand is achiral, while the framework of 8 is a typical 3D (3,4)-connected net. Compound 10 is the first example of Pb(II) wheel cluster [Pb(8)O(8)] units bridged by carboxylate groups. Compound 6 contains 1D chains which are further extended to a 3D structure by pi-pi interactions. Compound 9 consists of a 2D network constructed by Pb(II) centers and trans-chdc ligands. The structural differences between 7 and 8 and between 9 and 10 indicate the importance of solvents for framework formation of the coordination polymers. By varying the solvent the cis and trans conformations of H(2)chdc in 9 and 10 were separated completely. The photoluminescence and nonlinear optical properties of the coordination polymers have also been investigated.