Structure of N-nitroso-r-2,c-7-diphenylhexahydro-1,4-diazepin-5-one

C17H17N3O2, M(r) = 295.34, orthorhombic, P2(1)2(1)2(1), a = 7.659 (1), b = 12.741 (1), c = 15.095 (1) angstrom, V = 1473.19 (2) angstrom 3, Z = 4, D(m) = 1.33, D(x) = 1.32 Mg m-3, lambda(Cu K-alpha) = 1.5418 angstrom, mu = 0.68 mm-1, F(000) = 624, T = 295 K, R = 0.031 for 1549 unique observed reflections with I > 2.5-sigma(I). The seven-membered heterocyclic ring adopts a boat conformation flattened at the nitroso end of the ring. The substituent phenyl rings occupy pseudo-axial positions and the nitroso group is coplanar with the C(2), N(1), C(7) plane of the central ring. The crystal structure is stabilized by intermolecular N-H...O and weak C-H...O hydrogen bonds.

Negative differential resistance and memory effect in diodes based on 1,4-dibenzyl C60 and zinc phthalocyanine doped polystyrene hybrid material

Negative differential resistance (NDR) and memory effect were observed in diodes based on 1,4-dibenzyl C60 (DBC) and zinc phthalocyanine doped polystyrene hybrid material. Certain negative starting sweeping voltages led to a reproducible NDR, making the hybrid material a promising candidate in memory devices. It was found that the introduction of DBC enhanced the ON/OFF current ratio and significantly improved the memory stability. The ON/OFF current ratio was up to 2 orders of magnitude. The write-read-erase-reread cycles were more than 10(6), and the retention time reached 10 000 s without current degradation.

Column chromatographic purification free synthesis of long-chain monodisperse oligo(1,4-phenyleneethynylene)s: towards large-scale automatic synthesis of molecular wires

A facile, mild and rapid solid phase synthetic route free of column chromatographic purification to the synthesis of soluble monodisperse long-chain oligo(1,4-phenyleneethynylene)s is presented.

1,4-二丙氧基-2,3二氰基萘的晶体结构

用 Siemens P4四圆衍射仪,测得了1,4-二丙氧基-2,3-二氰基萘的晶体结构。晶体属单斜晶系,空间群为 C2/C。晶格参数 a=14.987(3)A,b=10.527(2),c=11.755(2),β=118.98°(3),晶胞体积 V=1622.4(6)3,Z=4,Dc=1.205Kg/m~3,μ(MoK_α)=0.079mm~(-1),F(000)=624,T=293(2)K_o晶体结构应用直接法,解出最后的偏离因子 R=0.0554[1425个Ⅰ≥2σ(Ⅰ)衍射点]。结构分析表明,萘环的1,4和2,3位碳原子上的氢原子分别被丙氧基和氰基所取代,由于取代基的引入使萘环的结构有所改变。

Levantamento pedológico detalhado (1:5.000) da Unidade de Pesquisa e Desenvolvimento de Tatuí (APTA Sudoeste Paulista - SAA - SP)

Relato da distribuição dos solos e de seus atributos identificados no levantamento pedológico detalhado da Unidade de Pesquisa e Desenvolvimento de Tatuí, Polo Regional Sudoeste da Agência Paulista de Tecnologia do Agronegócio (APTA-SAA-SP).

Levantamento pedológico semidetalhado (1:25.000) da microbacia da Água Três Unidos, município de Vera Cruz (SP).

2002

Síntese do levantamento de reconhecimento de baixa e média intensidade dos solos da Folha Cedro (Escala 1:100.000)

2007

Síntese do levantamento de reconhecimento de baixa e média intensidade dos solos da Folha Cedro (Escala 1:100.000)

2007

Síntese do levantamento de reconhecimento de baixa e média intensidade dos solos da Folha Jardim (Escala 1:100.000)

2007

Levantamento semidetalhado dos solos da bacia Rio Jardim-DF escala 1:50.000.

2000

Levantamento semidetalhado dos solos da bacia do Olaria - DF escala 1:30.000.

2000