March 15th of 2004 marked the 150th anniversary of the birth of Paul Ehrlich. He was the founder of modern chemotherapy and in fact coined the word and invented the science of chemical therapy. He and his chemist Al fred Bertheim were the first people to do three things: (1) identify a substance, either man-made or from natural products, which showed promise in killing certain invading organisms; (2) determine the correct structure of the active compound in this substance, and (3) modify the chemical structure of this compound to make it more potent to invading organisms and less harmful to the host.
The microwave spectrum of 2-oxazoline has been recorded from 12.4–40.0 GHz. Both Q-branch and R-branch assignments have been made for the ground and five vibrationally excited states of the ring puckering mode for both A - and B-type transitions. The components of the diple moment were determined by the Stark effect to be μa = 1.14±0.01, μb = 1.35±0.01, μc = 0.00±0.00, and μt = 1.77±0.01 D. The quadrupole coupling constants were found to have the following values: χa a = −3.54, χb b = 2.03, and χc c = 1.51 MHz. From the inertial defect Δc and the dipole moment, it is concluded that the heavy atom skeleton is planar. From the relative intensity measurements, the first excited state of the ring puckering vibration was found to have a frequency of 79±8 cm−1 and from a series of difference bands in the infrared spectrum, the ν = 0→1, 1→2, 2→3, 3→4, and 4→5 transitions were found to have the following frequencies: 74, 95, 103, 110, and 117 cm−1, respectively. The potential function governing the ring puckering motion was found to be of the form V = 22.2 (Z4+1.31Z2), where Z is the reduced ring puckering coordinate. The Raman spectra of gaseous, liquid, and solid 2-oxazoline was investigated from 0–3500 cm−1 and the infrared spectra of the gas and solid were recorded from 33–3500 cm−1. The vibrational assignment of the fundamentals is proposed which is consistent with the Cs conformation. The assignment is based on the gas-phase band contours, the depolarization values, and group frequency correlations. The number of lattice modes indicate that there are at least two molecules per primitive cell. The results are compared with those obtained for other similar five-membered rings.
g, 2.16 mmol) plus a mixture (0.090 g) of (CF3)2P(S)SCH3 contaminated with unreacted (CF3)2PS2H.Acknowledgment. We thank the National Research Council of Canada for financial support of this work and for a scholarship to L. F. D. We also thank G. Bigam, T. Brisbane, and Dr. T. Nakashima for much assistance with the nmr spectroscopic studies. Preliminary discussions of the exchange mechanism with Dr. R. W. Rudolph(University of Michigan) proved helpful to our understanding of the process and we wish to express our thanks. We also thank Dr.
breaking the N-S bond since the nitrogen atom already bears a positive formal charge of 1. Initial products from step 6 are then cis-HONNO-and 02SOB(OH)3. The latter hydrolyzes to sulfuric and boric acids while the cis-HONNO-decomposes as discussed earlier. Since B(OH)4-is unable to undergo additional coordination, the catalytic activity of boric acid on the decomposition of ON(S03-)NO-decreases at high pH.The proposed mechanism requires that the isotopic experiment of Clusius and Schumacher6 give equal amounts of "NNO and N"NO if carried out in the presence of boric acid. Unfortunately, the catalytic activity of boric acid was unknown to these authors and no such experiment was performed.Solvated heavy-metal ions also catalyze the decomposition of ON(S03-)NO-to form nitrous oxide and sulfate ion. Although their effect has not yet been the subject of a detailed study, we might anticipate that the activity of such metals arises from their coordination ability which would allow them to play a role similar to that which we have proposed for boric acid. The equal amounts of %'NO and Ni5N0 found with cupric ions as a catalyst6 are consistent with coordination at the SO3 group and indirectly offer support for the boric acid model. However, metal ions have more than one potential coordination site and could also promote decomposition through the formation of a chelate complex utilizing both oxygen atoms of the cis-hyponitrite group in ON(S03-)-NO-. Cleavage of the N-S bond then permits the two nitrogen atoms to become equivalent. With only one coordination site available boric acid cannot act in this way.Acknowledgments. This work was supported by the 6 7 8 9 PH Figure 3. Comparison of experimental values of k g / [ H + ] as a function of pH with the function k,K,[H+] / ( K B + [H+]) predicted by the proposed reaction mechanism: k,K, = 6.2 X IO' M-' sec-I, p = 0.50M, T = 25.0'; dashed line, K B = 1.29 X lo-' from ref 13; continuous line, K B = 6.8 X IO-'' from this work.eters are numerically smaller than those found for the hydrogen ion catalyzed pathway. N-Nitrosohydroxylamine-N-sulfonate and nitrohydroxa-mate, -ONN02-, may be viewed as cis-hyponitrite with an SO3 group or oxygen atom added to one of the nitrogen atoms. Since decomposition of neither nitrohydroxamate nor trans-hyponitrite shows specific catalysis by borate bufsome specific interaction between the SO3 group and B(OH)3 would appear to be involved in the transition state for the decomposition of the sulfonate. An attractive possibility is coordination of the boron atom to one of the oxygen atoms of the SO3 group as is found in B(HS04)4-in concentrated sulfuric acid.14 This coordination has the effect of reducing the electron density of the sulfur atom since one of its three oxygen atoms can no longer effectively donate electron density through pn-dn bonding. This facilitates (14) R. Flowers, R. J. Gillespie, and J. V. Oubridge, J. Chem. SOC., 1925 (1956).The infrared (45-3000 cm-I) and Raman (50-2700 cm-') spectra of H,P.BCl, and D,P.BCl, in the solid sta...
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