Inorganic-organic hybrid framework solids

Recent developments in the area of hybrid structures are overviewed with special emphasis on iron phosphate-oxalate materials. The structure of the iron phosphate-oxalates consists of iron phosphate chains or layers that are connected by oxalate moieties completing the architecture. The compounds exhibit interesting magnetic properties originating from the super-exchange interactions that are predominantly anti-ferromagnetic, involving the iron phosphates and the oxalate moieties. One of the materials,IV, also exhibits interesting adsorptive properties reminiscent of aluminosilicate zeolites. The aluminum phosphate-oxalate,VII, indicates that hybrid structures can be formed with zeolite architecture

Pyridine-and imidazoledicarboxylates of zinc: hydrothermal synthesis, structure, and properties

The reaction of hetrocyclic dicarboxylic acids, such as pyridine-2,5-dicarboxylic acid and imidazole-4,5-dicarboxylic acid, under hydrothermal conditions in the presence of an appropriate zinc salt yields three new zinc coordination polymers 0∞[{Zn2(H2O)4}{C5H3N(COO) 2}2] (1), 1∞ [{Zn(C12H8N2)}{C5H3N(COO) 2}·0.5H2O] (2), and 1∞ [{Zn(C12H8N2)}{C3HN2(COO) 2}] (3). While 1 forms with a zero-dimensional molecular rectangular box structure, 2 and 3 have zig-zag one-dimensional chain structures. The Zn2+ ions are coordinated by both the carboxylate oxygen atoms and also by the nitrogen atoms of the heterocycles. The 1,10-phenanthroline molecules in 2 and 3 act as a secondary ligands and occupy the inter-chain spaces. The moderate hydrogen-bond interaction energy in 1 and the π···π interactions in 2 and 3 appear to play an important role for the structural stability. The structures of 2 and 3 appear to be related, even though they are formed with different carboxylic acids. All three compounds exhibit photoluminescence at room temperature

Conducted electromagnetic interference mitigation in super-lift Luo-converter for electric vehicle applications

In this article, a digital chaotic pulse width modulation (DCPWM)-dependent electromagnetic interference (EMI) noise attenuating procedure has been implemented. With the aid of a field programmable gate array (FPGA), a randomized carrier frequency modulation with a fixed duty cycle has been generated through chaotic carrier frequency, and this process is called DCPWM. Conducted EMI suppression is achieved in a 200 kHz, 40 W elementary positive output super lift Luo (EPOSLL) converter using the DCPWM technique. The results are compared and validated with periodic PWM over DCPWM in simulation and hardware with electromagnetic compatibility (EMC) standards. Besides, 9 dBV (2.81 V) of conducted EMI noise has been minimized in the DCPWM approach against periodic pulse width modulation method for the EPOSLL converter in electric vehicles applications

New open-framework layered tin(II ) phosphates intercalated with amines

Two new Sn(II) phosphate materials, I and II, have been synthesized hydrothermally using 1,3-diaminopropane and 1,3-diamino-2-hydroxypropane as structure-directing organic amines. The solids I and II have layered architectures and are isostructural. The structures consist of vertex sharing trigonal-pyramidal SnO and tetrahedral PO moieties forming infinite layers possessing 4- and 8-membered apertures. The interlamellar space is occupied by the protonated amine molecules which interact with the framework through hydrogen bonding. Crystal data for compound I: [NH(CH)NH]2[SnPO], M=501.9, monoclinic, space group C2/c, a=18.097(1), b=7.889(1), c=9.151(1)Å, β=111.84(1)°, V=1212.6(2)Å, Z=4, R=0.033 and R=0.061 [791 observed reflections with I=2σ(I )]; compound II [NH(CHCHOHCH)NH] 2[SnPO], M=517.9, monoclinic, space group C2/c, a=18.133(1), b=7.858(1), c=9.344(1)Å, β=111.3(1)°, V=1240.5(2)Å, Z=4, R=0.040 and R=0.11 [867 observed reflections with I=2σ(I)]

1-Benzoyl-4-(4-methyl­phen­yl)phthal­azine

In the title mol­ecule, C22H16N2O, the tolyl and benzoyl rings make dihedral angles 50.2 (5) and 56.4 (5)°, respectively, with the phthalazine ring system while the dihedral angle between the tolyl and benzoyl rings is 0.70 (4)°. The crystal structure is stabilized by inter­molecular C—H⋯O and C—H⋯N hydrogen bonds, as well as weak C—H⋯π inter­actions

New photocatalysts based on mixed-metal pyridine dicarboxylates

New photocatalytically active isostructural two-dimensional mixed metal-pyridine dicarboxylates, [M(H2O)3Co{C5N1H3(COO) 2}3])∞], M = Gd (1), Dy (2) and Y (3) have been prepared under hydrothermal conditions. The structure consists of a network of MO6(H2O)3, CoO3N3 polyhedral units connected by the pyridine dicarboxylates forming two-dimensional layers, which are arranged in an AAAA... fashion. The photocatalytic studies on 1 - 3 indicate that they are active catalysts for the degradation of simple organic dyes, such as Remazol brilliant blue R (RBBR) and Orange G (OG) in the presence of UV light. The compounds have also been characterized by powder XRD, IR, TGA, UV-Vis and magnetic studies

(3-Ethyl-6,7-dimeth­oxy­naphthalen-1-yl)(phen­yl)methanone

The asymetric unit of the title mol­ecule, C21H20O3, contains two crystallographically independent mol­ecules, A and B, which differ in the orientation of the ethyl group substituted on the naphthalene system; the dihedral angles between the ethyl group and the naphthalene system are 7.4 (3) and 68.1 (3)°, respectively, for mol­ecules A and B. The dihedral angles between the benzoyl and naphthalene groups are 64.7 (7) and 69.4 (8)°, respectively, for mol­ecules A and B. The crystal structure features four aromatic π–π stacking interactions [centroid–centroid distances = 4.181 (1), 3.891 (1), 4.423 (1) and 4.249 (1) Å]

Synthesis, structure and optical properties of rare-earth benzene carboxylates

Two series of rare-earth isophthalates of the general formula, [M2(H2O)] [{C6H4(COO)2}2{C6H4(COOH)(COO)}2]·H2O, M = La (I), Pr (Ia), and Nd (Ib) and [M2(H2O)2][{C6H4(COO)2}3]·H2O, M = Y (II), Gd (IIa), and Dy (IIb) have been prepared by the reaction of the corresponding trivalent lanthanide salts and isophthalic acid under mild hydrothermal conditions. The La (I), Pr (Ia) and Nd (Ib) have MO9 polyhedra connected to the isophthalate anions forming a two-dimensional structure, whereas Y (II), Gd (IIa) and Dy (IIb) have MO7 and MO8 polyhedral units connected to the isophthalate anions forming a different, but related two-dimensional structure. Both the structures are stabilized by hydrogen bonding and π···π/CH···π interactions. Partial substitution of Eu and Tb (2 and 4%) at the La (I) and Y (II) sites give rise to characteristic red/pink or green luminescence, indicating a ligand-sensitized metal-centered emission. The Nd (Ib) compound shows interesting UV and blue emission through an up-conversion process