Symbols and Abbreviations,continued REAGENTS AND SOLVENTS,continued PCC pyridinium chlorochromate,CrO3·HC·N CH3H HH CH3 SiaBH disiamylborane H- -S-B-C- C-H CH3 CH3 CH3 CH3 THF tetrahydrofuran SPECTROSCOPY R infrared spectroscopy NMR nuclear magnetic resonance spectroscopy MS mass spectrometry UV ultraviolet spectroscopy parts per million,a unit used in NMR hertz,cycles per second.a unit of frequency MHz megahertz,millions of cycles per second TMS tetramethylsilane,(CH)4Si,the reference compound in NMR s.d.t.q singlet,doublet,triplet.quartet.referring to the number of peaks an NMR absorption gives nm anometers.10meters(usually used as a unit of wavelength m/z mass-to-charge ratio,in mass spectrometry 6 in NMR,chemical shift value,measured in ppm 入 wavelength frequency OTHER a,ax axial (in chair forms of cyclohexane) e,eg equatorial (in chair forms of cyclohexane) HOMO highest occupied molecular orbital LUMO lowest unoccupied molecular orbital NR no reaction o.m.p ortho,meta,para (positions on an aromatic ring) A when written over an arrow:"heat";when written before a letter:"change in" 8,6 partial positive charge,partial negative charge energy from electromagnetic radiation(light) [alp specific rotation at the D line of sodium(589 nm)Symbols and Abbreviations, continued REAGENTS AND SOLVENTS, continued PCC pyridinium chlorochromate, Cr03· HCI • N� ') CH3 H H H CH3 I I I I I Sia2BH disiamylborane H - C-C-B-C-C-H I I I I CH3 CH3 CH3 CH3 THF tetrahydrofuran o SPECTROSCOPY IR NMR MS UV ppm Hz MHz TMS s, d, t, q nm mJz 8 A v OTHER a, ax e, eq HOMO LUMO NR 0, m,p infrared spectroscopy nuclear magnetic resonance spectroscopy mass spectrometry ultraviolet spectroscopy parts per million, a unit used in NMR hertz, cycles per second, a unit of frequency megahertz, millions of cycles per second tetramethylsilane, (CH3)4Si, the reference compound in NMR singlet, doublet, triplet, quartet, referring to the number of peaks an NMR absorption gives nanometers, 10-9 meters (usually used as a unit of wavelength) mass-to-charge ratio, in mass spectrometry in NMR, chemical shift value, measured in ppm wavelength frequency axial (in chair forms of cyclohexane) equatorial (in chair forms of cyclohexane) highest occupied molecular orbital lowest unoccupied molecular orbital no reaction artha, meta, para (positions on an aromatic ring) when written over an arrow: "heat"; when written before a letter: "change in" partial positive charge, partial negative charge energy from electromagnetic radiation (light) specific rotation at the D line of sodium (589 nm) ix