Synthesis and Crystal Structure of 1,3-Trans-1,4-cis- 3,4-di(4-bromophenyl)-1',2',3'-trihydro-1-hydroxy- benzo[g]bicyclo[3.3]octane-2-spiro-2'-indene-1'-one

The title compound C35H30Br2O3 （C32H24Br2O2·CH3COCH3） has been synthesized by the dimerization of 2-（4＇-bromobenzal）-1-indenone induced by low-valent titanium reagent, and characterized by elemental analysis, IR,^1H NMR and X-ray single-crystal diffraction. The crystal belongs to triclinic, space group P1^- with a = 10.273（7）, b = 11.036（7）, c = 13.944（9） ,A°, a = 73.972（9）, β =76.577（10）,γ= 88.871（10）°, V = 1476.3（17）A°^3, Mr = 658.41, Z = 2, Dr = 1.481 g/cm^3, μ（MoKa） = 2.780 mm^-1, F（000） = 668, the final R = 0.0452 and wR = 0.0975. X-ray analysis reveals that the two cyclopentane rings spiro-fused each other adopt envelope conformations, while the other cyclopentane ring （C（1）--C（2）-C（7）-C（9）） is coplanar. In addition, there is a classical intermolecular hydrogen bond O（1）-H（1）...O（2） connecting the adjacent molecules into dimers.

Preparation and Spectrophotometric Study of Reagent 2-[2-（6-chloro benzothiazolyl） azo]-Resorcinol as an Analytical Reagent for Determination of Nickel （11） and Copper （11） Ions

The present paper describes the preparation of new organic reagent 2-[2-（6-chloro benzothiazolyl） azo]-resorcinol （6-CIBTAR = LH2） and used for the spectrophotometric determination of traces microgram amount of nickel （II） and copper （II） was found to form Ni（II）-CIBTAR at pH 7.5 giving a green coloured complex with maximum absorption at wavelength 636 nm and copper （II） was found to from Cu（II）-CIBTAR at pH 6.5 giving green bluish coloured complex with maximum absorption at wavelength 648 nm. The molar absorptivity （~） of the complexes are 0.3695 ~ 104 L.moll-cml and 0.3933 ~ 154 L＇mol＇l.cm1 for Ni（II） and Cu（II） respectively. Calibration curves for the determination of nickel（II） and copper （II） conformed to beers law over the concentration rang of （1-20） μg.mL-1. The DL （detection limit）, RSD （relative standard deviations）, RE （relative errors） and recovery for Ni（II） and Cu（II） complexes were found to be D.L = 0.45, 0.61; R.S.D% = 1.81, 2.04; Erei% = 1.3, 0.86 and Re% = 98.7, 99.14 respectively. The analytical data show the metal to reagent ratio （mole ratio method; M：L） in Ni（II） and Cu（II） complexes are 1：2.

Synthesis and Thermal Decomposition Mechanism of Rare Earth (RE=La, Y, Gd) Salicylates

The rare earth (RE=La, Y, Gd) salicylates were synthesized by the rheological phase reaction method. The complexes were characterized by elemental analysis, infrared spectra (IR), X-ray powder diffraction (XRD) and thermal gravity analysis (TG). They can be represented by general formula RE(HSal)3 (RE=La, Y, Gd; HSal= C6H4(OH)COO). The crystals of them are monoclinic and have layered structure. The mechanism of thermal decomposition of rare earth salicylates was studied by using TG, DTA, IR and gas chromatography-mass spectrometry (GC-MS). The thermal decomposition of the rare earth salicylates in nitrogen gas proceeded in three stages: firstly, they were decomposed to form RE2(Sal)3(Sal=C6H4OCOO) and salicylic acid; then, RE2(Sal)3 were decomposed further to form RE2O(CO3)2 and some organic compounds; finally, RE2O(CO3)2 were decomposed to form rare earth metal oxides (RE2O3) and carbon dioxide. The organic compounds obtained from the second step of the reaction are mainly dibenzofuran, xanthenone, 6H-benzo[c]chromen-6-one, 6-phenyl-6H-benzo[c]chromene, and 1,3-diphenyl-1, 3-dihydro-2-benzofuran.