Near-infrared carbonyl-associated bands

Infrared spectra were consistent with the presence of both reactants and the formation of a new Sb bond. For the product of triphenylantimony dichloride and ticarcillin a new band about 1204 cm" (all IR bands given in cm" ) is assigned to the Sb-0 stretch. The upward shift in the salt carbonyl from about 1598 to 1645 was consistent with Sb-O-CO-R bond formation. A new band around 1280 was assigned to the Sb-O bond formation. An Sb-Ph stretch was found at 1440, smaller than that found for triphenylantimoney dichloride itself at 1434. Other phenyl-associated bands were found at 720 and 680, near those for triphenylantimony dichloride itself with bands at 732 and 686. The broad band centered at 3432 was assigned to NH stretching. The bands about 3059 were assigned to the C-H aromatic stretch present in the antimony moiety whereas those centering above this result from the C-H stretch in the ticarcillin. A series of bands from about 2990 to 2920 were derived from the C-H aliphatic found in ticarcillin. 

Thus, the region 2100-1830 cm 1 can be covered. This allows us to monitor CO(v,J) by resonance absorption and various M(CO)n [n = 3-6] as a result of near coincidences between the CO laser lines and the carbonyl stretching vibrations of these species. The temporal response of the detection system is ca. 100 ns and is limited by the risetime of the InSb detector. Detection limits are approximately 10 5 torr for CO and M(CO)n. The principal limitation of our instrumentation is associated with the use of a molecular, gas discharge laser as an infrared source. The CO laser is line tuneable laser lines have widths of ca. lO cm 1 and are spaced 3-4 cm 1 apart. Thus, spectra can only be recorded point-by-point, with an effective resolution of ca. 4 cm 1. As a result, band maxima (e.g. in the carbonyl stretching... 

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