Articles you may be interested inAnalysis of the rotational spectrum of methylene ( C H 2 ) in its vibronic ground state with an Euler expansion of the Hamiltonian Determination of the proton tunneling splitting of the vinyl radical in the ground state by millimeter-wave spectroscopy combined with supersonic jet expansion and ultraviolet photolysis

The propargyl radical (CH2C≡CH) produced by the ArF excimer laser photolysis of allene was observed by time-resolved infrared diode laser spectroscopy. More than one hundred and fifty absorption lines have been assigned to the ν6 (CH2-wagging) fundamental band of propargyl. Most of the absorption lines were observed as doublets due to the spin–rotation interaction in the 2B1 ground electronic state. The rotational and spin–rotation interaction constants derived for the ground vibrational state are, A0=9.608 47(36), B0=0.317 674(24), C0=0.307 098(24), εaa=−0.017 58(95), and εbb=−0.000 355(76) cm−1, where the figures in parentheses are 2.5 times standard deviations to be attached to the last digit. The ν6 band origin is 687.176 03(62) cm−1, consistent with the infrared spectrum observed in the argon matrix. Anomalously large vibrational changes in the A rotational constant and the ΔK centrifugal distortion constant are accounted for by the a-type Coriolis interaction between the ν6 and ν10 states, where ν10 is the CH2-rocking vibration.

The infrared spectrum of the iron dicarbonyl radical Fe(CO)2 produced in a supersonic jet expansion by the excimer laser photolysis of iron pentacarbonyl Fe(CO)5 was observed by time-resolved infrared diode laser spectroscopy. About 170 transitions, each split into one or two fine structure components, were assigned to the ν3 (CO antisymmetric stretch) band of Fe(CO)2. The assignment was greatly facilitated by spectral simplification caused by rotational as well as vibrational cooling in the supersonic jet. It was observed that lines are missing at alternate J quantum numbers in each spin component, which confirmed that Fe(CO)2 is a linear molecule with D∞h symmetry and that the electronic ground state is of 3Σg− symmetry. The rotational and centrifugal distortion constants in the ground state were determined to be B0=1414.675(46) MHz and D0=0.3077(74) kHz, respectively. The spin–spin interaction constants obtained, λ0=655.3(42) GHz, is comparable with that of the FeCO radical, λ0=684.470(51) GHz. The ν3 band origin was determined to be 1928.184335 (82) cm−1. The figures in parentheses are uncertainties (1σ) in units of the last digit.

ICP-QMS/QMS was applied to whole blood samples to determine the quantity of trace As. It was found that Fe also causes polyatomic interference with As in conventional ICP-QMS, in addition to Ca and Cl, and ICP-QMS/QMS can remove these interferences in mass-shift mode using O2 as reaction gas. The ICP-QMS/QMS technique allows the determination of As at sub-ng mL -1 levels.