A critical study of the cold vapor atomic absorption and fluorescence instrumentation for the analysis of mercury is described. Some of the important modifications involve the reduction vessel, absorption cell, fluorescence cell, and radiation source. The new modified systems have much greater calibration sensitivities and lower detection limits than those...
Described herein is the synthesis of an uncharged stereoregular oligonucleotide
analog consisting of cytosine bases linked at specific intervals to a polyamide backbone
derived from (L)-glutamic acid. Preparation of this analog entailed borane reduction of
(L)- pyroglutamic acid to give optically pure lactam alcohol 9. Tosylation and alkylation
with cytosine...
I. Lithium alkyl and aryl monosubstituted cyclooctatetraenide
dianions (Li₂ C₈H₇-R; R = methyl, n- butyl, sec- butyl, tert- butyl,
phenyl and benzyl) were synthesized by the reaction of the appropriate
organolithium reagent with cyclooctatetraene in diethyl ether or
tetrahydrofuran. The reaction occurred cleanly and with good yield
of lithium monosubstituted...
Enantioselective epoxidation of crotyl alcohol, followed
by a cuprate mediated methylation, gave a 1:1 mixture of
(2S) -3- methyl -1,2- butanediol and (2R,3S)-2-methy1-1,3-
butanediol. The latter was separated as its 2,4,6-trimethylbenzenesulfonate
derivative and converted via the
iodide to the corresponding phosphonium salt. The separated
butanediol derivatives were independently transformed
to...
The carbon is photoelectron spectrum of CO₂ has been measured with very high photon energy resolution. The natural lifetime of the carbon is hole state has been determined from a series of spectra taken at photon energies of 308, 320, and 330 eV. The measured values of the lifetimes show...
The two sulfur isotopomers of sulfur trioxide, ³²S¹⁶O₃ and ³⁴S¹⁶O₃, have been studied via high resolution infrared and Coherent anti-Stokes Raman (CARS) spectroscopy. The v₁ symmetric SO stretching Q-branches observed by the latter are quite different, being especially complex for ³²S¹⁶O₃ Understanding this band structure required analysis of infrared-active hot...
Fluorinated alkyl substances, which can be persistent, toxic, and
bioaccumulative, have been quantitated in many densely populated and
remote regions, including in air, surface waters, groundwater, and biota;
however, little is known about their transport or behavior in the environment.
Wastewater effluent is one of the principal routes for introducing...