The chemistry department at Washington & Jefferson College implemented an "organic first" curriculum in the fall semester of 2005. Assessment data suggest that the net impact of this change for the department and associated constituencies has been positive: (i) Student outcomes have generally not been impacted by the curricular change, though a significant improvement in student performance on a standardized analytical exam has been observed. (ii) The department has attracted more majors, and can use faculty resources differently as a two-semester general chemistry sequence is no longer offered. (iii) The biology program reports greater student success in introductory biology, in part because of the organic chemistry background students now acquire earlier.

Candy, an everyday treat, is a convenient theme for teaching chemistry. Making candy incorporates solution concentration, colligative properties, and phase transformations while flavoring and color reflect synthesis or extraction. In this article, a nonscience major laboratory course on candy chemistry is presented. The course combines laboratory experiments and candymaking exercises, illustrating general chemistry principles and data collection. For example, students investigate crystal formation with rock candy and fudge, browning reactions with UV−vis spectroscopy and caramels, enzyme kinetics with polarimetry and cherry cordials, and freezing point depression with temperature measurements and ice cream. Imitation and natural flavors are obtained through Fischer esterification and distillation, respectively, while colorants are characterized through chromatography and spectroscopy. The course incorporates statistics through sensory analysis and color distribution. Student assessment and feedback as well as a poster/tasting session are also described.

The microwave spectra of CH3CH2PH2 11BH3, CH3CH2PH2 10BH3, and CH3CH2PH2 11BD3 have been recorded in the region 18.0–39.0 GHz and those of CH3CH2PD2 11BH3 and CH3CH2PD2 11BD3 in the range 26.5–39.0 GHz. a-type transitions were observed and R-branch assignments have been made for all isotopes in the ground vibrational state. From the relative intensities of the microwave transitions, the Stark effect, and the experimental rotational constants, it has been determined that the assigned spectra result from the trans conformer which is believed to be more stable than the gauche form at ambient temperature. The dipole moment components for trans-ethylphosphine–borane were determined from the Stark effect to be ‖μa‖ = 4.66±0.01, ‖μb‖ = 1.34±0.03, and ‖μt‖ = 4.85±0.02 D. With reasonable assumptions for the ethyl moiety, the following structural parameters for trans-ethylphosphine–borane were calculated: r(B–P) = 1.914±0.018 Å, r(B–H) = 1.205±0.013 Å, r(P–H) = 1.408±0.016 Å, r(P–C) = 1.823±0.016 Å, ∢BPC = 115.0°±1.1°, ∢PBH = 106.1°±3.4°, ∢CPH = 103.4°±3.7°, and ∢PCC = 115.1°±2.5°. These results are compared to similar quantities in some analogous molecules.

The far-infrared spectrum of gaseous 2-chloropropenoyl fluoride, CH2 CClCFO, has been recorded at a resolution of 0.10 cm−1 in the region of 350–35 cm−1. The fundamental asymmetric torsional frequencies of the more stable s-trans (two double bonds oriented trans to one another) and the high energy s-cis conformations have been observed at 67.80 and 49.96 cm−1, respectively, each with several excited states falling to lower frequencies. From these data the asymmetric torsional potential function governing the internal rotation about the C–C bond has been determined. The potential coefficients are V1 =−125±1, V2 =1586±6, V3 =375±2, V4 =−36±2, and V5 =−65±1 cm−1. The s-trans to s-cis and s-cis to s-trans barriers have been determined to be 1755 and 1570 cm−1, respectively, with an energy difference between the conformations of 185±9 cm−1 (529±26 cal/mol). From studies of the Raman spectrum at variable temperatures, the conformational enthalpy difference has been determined to be 176±40 cm−1 (503±114 cal/mol) and 625±51 cm−1 (1787±146 cal/mol) for the gas and liquid, respectively. A complete assignment of the vibrational fundamentals observed from the infrared spectra (3500–50 cm−1) of the gas and solid and the Raman spectra (3200–10 cm−1) of all three physical states is proposed. All of these data are compared to the corresponding quantities obtained from ab initio Hartree–Fock gradient calculations employing both the 3-21G* and 6-31G* basis sets. Additionally, complete equilibrium geometries have been determined for both rotamers. The results are discussed and compared with the corresponding quantities obtained for some similar molecules.

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