Thermal Decomposition of CF3C(O)O2NO2, CClF2C(O)O2NO2, CCl2FC(O)O2NO2, and CCl3C(O)O2NO2

Haloacetyl, peroxynitrates are intermediates in the atmospheric degradation of a number of haloethanes. In this work, thermal decomposition rate constants of CF₃C(O)O₂NO₂, CClF₂C(O)O₂NO₂, CCl₂FC(O)O₂NO₂, and CCl₃C(O)O₂NO₂ have been determined in a temperature controlled 420 l reaction chamber. Peroxynitrates (RO₂NO₂) were prepared in situ by photolysis of RH/Cl₂/O₂/NO₂/N₂ mixtures (R = CF₃CO, CClF₂CO, CCl₂FCO, and CCl₃CO). Thermal decomposition was initiated by addition of NO, and relative RO₂NO₂ concentrations were measured as a function of time by long-path IR absorption using an FTIR spectrometer. First-order decomposition rate constants were determined at atmospheric pressure (M = N₂) as a function of temperature and, in the case of CF₃C(O)O₂NO₂ and CCl₃C(O)O₂NO₂, also as a function of total pressure. Extrapolation of the measured rate constants to the temperatures and pressures of the upper troposphere yields thermal lifetimes of several thousands of years for all of these peroxynitrates. Thus, the chloro(fluoro)acetyl peroxynitrates may play a role as temporary reservoirs of Cl, their lifetimes in the upper troposphere being limited by their (unknown) photolysis rates. Results on the thermal decomposition of CClF₂CH₂O₂NO₂ and CCl₂FCH₂O₂NO₂ are also reported, showing that the atmospheric lifetimes of these peroxynitrates are very short in the lower troposphere and increase to a maximum of several days close to the tropopause. The ratio of the rate constants for the reactions of CF₃C(O)O₂ radicals with NO₂ and NO was determined to be 0.64 ± 0.13 (2σ) at 315 K and a total pressure of 1000 mbar (M = N₂). © 1994 John Wiley & Sons, Inc.     

The cyclic vanadylacetate (C24H20P)[V4O8(C2H3O2)4(NO3)]

In the title complex, tetraphenylphosphonium μ₄‐nitrato‐κ⁴O‐cyclo‐tetrakis(μ‐acetato‐O:O′)tetra‐μ‐oxo‐tetrakis[oxovana‐dium(V)], the anion lies about a twofold axis and consists of the cyclic [V₄O₈] unit coordinated by four acetato ligands with interatomic V?V distances of 3.269 (1) and 3.273 (1) Å. The double‐bonded O atom [N=O 1.102 (6) and N—O 1.268 (4) Å] of the nitrato ligand links the four V atoms with V—O bond distances of 2.613 (2) and 2.813 (2) Å. The negative charge of the complex is balanced by tetraphenyl­phosphonium cations occupying the Na positions in the NaCl‐type ionic packing of the structure.     

(C26H40N2O4)[Ln(NO3)5H2O]的合成及其铕缔合物的晶体结构

合成了4个新型的稀土化合物(C₂₆H₄₀N₂O₄)[Ln(NO₃)₅H₂O](Ln=Pr,Nd,Sm,Eu),采用元素分析和红外光谱表征,用四圆衍射仪测定了其中(C₂₆H₄₀N₂O₄)[Eu(NO₃)₅H₂O]的晶体结构,属三斜晶系,P1空间群,晶胞参数:α=0.9100(4)nm,b=1.3560(3)nm,c=1.6463(4)nm;α=68.62(2)°,β=74.84(3)°,γ=87.50(2)°;Z=2.中心铕离子由5个硝酸根的10个氧原子和1个水分子中的氧原子配位,配位数是11.1,7,10,16-四氧-4,13-二氮杂-N,N'-二苄基环十八烷(N,N'-二苄基穴醚(2,2))未参与配位.