Thaer Assaad

\ 2,2,2-Trifluoro- N -(1a,2,7,7a-tetrahydronaphtho[2,3- b ]oxiren-3-yl)\ acetamide by X-ray powder diffraction

The title compound, C(12)H(10)F(3)NO(2), an important precursor in the preparation of benzovesamicol analogues for the diagnosis of Alzheimers disease, was prepared by the epoxidation of 5,8-dihydronaphthalen-1-amine using 3-chloroperoxybenzoic acid. The structure was determined by X-ray powder diffraction, multinuclear NMR spectroscopy and FT-IR spectroscopy. A pair of molecules form intermolecular N-H...O hydrogen bonds, involving the amino and oxirene groups, to produce a dimer.

Crystal structure of bis-[(1-ammonio-1-phosphono-eth-yl)phospho-nato]tetra-aqua-cadmium dihydrate: a powder X-ray diffraction study.

In the compound [CdL 2(H2O)4]·2H2O [L = (1-ammonio-1-phosphonoethyl)phosphonate, C2H8NO6P2 −], the CdII ion is situated on an inversion centre being coordinated by four aqua molecules in the equatorial plane and two deprotonated phosphonate O atoms from two L ligands in the axial positions in a distorted octahedral geometry. Each ligand L exists in a zwitterionic form, and with an intramolecular O—H⋯O interaction forming an S(6) ring motif and two intramolecular N—H⋯O interactions each generating an S(5) ring motif. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link complex molecules into a three-dimensional network with voids of 38 Å3 filled with ordered lattice water molecules, which are also involved in O—H⋯O hydrogen bonding.

Poly[[μ-(1-azaniumylethane-1,1-diyl)bis(hydrogen phosphonato)]sodium]: a powder X-ray diffraction study.

The title two-dimensional coordination polymer, [Na(C₂H₈NO₆P₂)]n, was characterized using powder X-ray diffraction data and its structure refined using the Rietveld method. The asymmetric unit contains one Na⁺ cation and one (1-azaniumylethane-1,1-diyl)bis(hydrogen phosphonate) anion. The central Na⁺ cation exhibits distorted octahedral coordination geometry involving two deprotonated O atoms, two hydroxy O atoms and two double-bonded O atoms of the bisphosphonate anion. Pairs of sodium-centred octahedra share edges and the pairs are in turn connected to each other by the biphosphonate anion to form a two-dimensional network parallel to the (001) plane. The polymeric layers are connected by strong O-H∙∙∙O hydrogen bonding between the hydroxy group and one of the free O atoms of the bisphosphonate anion to generate a three-dimensional network. Further stabilization of the crystal structure is achived by N-H∙∙∙O and O-H∙∙∙O hydrogen bonding.

Poly[[μ-(1-ammonio-ethane-1,1-di-yl)bis-(hydrogenphospho-nato)]diaquachloridodisodium]: a powder X-ray diffraction study.

The title compound, [Na2(C2H8NO6P2)Cl(H2O)2]n, has a polymeric two-dimensional structure extending parallel to (001). The asymmetric unit contains two Na+ cations located on a centre of symmetry and on a mirror plane, respectively, one half of a bis-phosphonate anion (the entire anion is completed by mirror symmetry), one chloride anion on a mirror plane and one water molecule in general positions. The two Na+ cations exhibit distorted octahedral NaCl2O4 coordination polyhedra, each consisting of two deprotonated O atoms of the bis-phosphonate anion, of two water molecules and of two chloride anions. Strong O—H⋯O hydrogen bonds between the –OH group and one of the free O atoms of the bis-phosphonate anion connect adjacent layers along [100], supported by N—H⋯Cl interactions. Intralayer O—H⋯O and N—H⋯O hydrogen bonds are also observed.

New amino bisphosphonate compound for skeletal imaging: Comparison study with methylenediphosphonic acid (MDP) and (1-hydroxyethane-1,1-diyl) diphosphonic acid (HEDP)

Abstract A novel bisphosphonate derivative (1-aminoethane-1,1-diyl)diphosphonic acid (AEDP) has been prepared and successfully labeled with 99mTc at high labeling yields. The in vivo biodistribution of 99mTc-AEDP has been investigated and compared with two reference compounds Tc-99m methylene diphosphonate (99mTc-MDP) and Tc-99m (1-hydroxyethylidene) diphosphonate (99mTc-HEDP). The biodistribution studies have demonstrated a high uptake of the radiotracer 99mTc-AEDP in the bone and a rapid clearance from the blood (such as the two technetium-labeled bone imaging agents in current use: 99mTc-MDP and 99mTc-HEDP). Additionally, the scintigraphic images of 99mTc-AEDP in normal rats have revealed high selective skeletal uptake.

Powder X-ray study of racemic (2RS,3RS)-5-amino-3-[4-(3-methoxyphenyl)piperazin-1-yl]-1,2,3,4-tetrahydronaphthalen-2-ol.

The title compound, C(20)H(25)N(3)O, an important precursor for the preparation of benzovesamicol analogues for the diagnosis of Alzheimers disease, has been synthesized and characterized by FT-IR, and (1)H and (13)C NMR spectroscopic analyses. The crystal structure was analysed using powder diffraction as no suitable single crystal was obtained. The piperazine ring has a chair conformation, while the cyclohexene ring assumes a half-chair conformation. The crystal packing is mediated by weak contacts, principally by complementary intermolecular N-H···O hydrogen bonds that connect successive molecules into a chain. Further stabilization is provided by weak C-H···N contacts and by a weak intermolecular C-H···π interaction.