Permetalloplumbanes: Preparation of [Pb{Co(CO)3(L)}4] and [Pb{Fe(CO)2(NO)(L)}4].: Complexes containing four transition metal to lead bonds (L = tertiary arsine,phosphine or phosphite).

The sole and unexpected products from the reactions of a variety of lead (II) and lead (IV) compounds with [Co₂(CO)₆(L)₂] complexes (L = tertiary arsine, phosphine, or phosphite) in refluxing benzene solution are the blue, air-stable percobaltoplumbanes [Pb{Co(CO)₃(L)}₄]. These have also been obtained from the reaction of Na[Co(CO)₃(L)] (L  PBu₃ⁿ) with lead (II) acetate which with Na[Fe(CO)₂(NO)(L)] forms the isoelectronic [Pb{Fe(CO)₂(NO)(L)}₄] [L  P(OPh)₃]. The IR spectra of the complexes in the v(CO) and v(NO) regions are consistent with tetrahedral PbCo₄ or PbFe₄ fragments, trigonal bipyramidal coordination about the cobalt or iron atoms and linear PbCoAs, PbCoP, or PbFeP systems. Unlike [Pb{Co(CO)₄}₄], our complexes do not dissociate to [Co(CO)₃(L)]^? or [Fe(CO)₂(NO)(L)]^? ions when dissolved in donor solvents.     

Investigation of aluminum interferences using the stabilized temperature platform furnace

Al was determined in the stabilized temperature platform furnace with very few interferences. No interferences were found for several metal nitrates, sulfates or phosphates, or for NaCl. The Al absorbance signal was delayed in the presence of MgCl₂ but there was no interference. This led to the use of 50 μg Mg(NO₃)₂ as a matrix modifier for Al. There were no interferences for CaCl₂ but it was particularly important to use new pyrolytically coated tubes to avoid “aging” effects. CuCl₂ provided a very persistent interference that was reduced when the Mg(NO₃)₂ matrix modifier was used that permitted a char temperature of 1700°C. Perchloric acid interferences were severe with improperly coated graphite tubes but did not exist up to 0.5 M HClO₄ when the new pyrolytically coated tubes were used. A serum Al method was tested briefly and no problems were found. Al was determined in seawater with no influence from the salinity of the sample and less than 0.6 μg/1 Al in seawater could be detected.     

Regiochemical control in the diels-alder reactions of substituted naphthoquinones: orientation in the synthesis of benz[a]anthraquinones

The regioselectivity in the Diels-Alder reactions of styrene with certain substituted 1,4-naphthoquinones was explored. The results were consistent with predictions based upon analysis of dione polarization.     

NH3+自由基离子的电子自旋共振

本文研究了俘获于掺杂VO⁺⁺离子的(NH₄)₂Zn(SO₄)₂·6H₂O单晶中NH₃⁺自由基离子的ESR.从实验上分别测出π电子自由基NH₃⁺的¹⁴N和¹⁵N核超精细分裂.结果表明,氮核超精细偶合张量具有近似于圆柱形对称。对于¹⁵N来说,A₁₁=44.8,A₂₂=19.3,A₃₃=17.8高斯.对于¹⁴N来说,A₁₁=31.1,A₂₂=12.5,A₃₃=11.8高斯.在室温下,NH₃⁺自由基绕A₁₁方向作圆锥体运动.文中最后讨论了NH₃⁺自由基离子的可能生成机理。