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The nuclear induction spectrometer which has previously been described was used to measure the magnetic moments of a number of nuclei. These values are without corrections of any kind and are based upon a value for the magnetic moment of the proton of (2.79348±0.00034) nuclear magnetons. The experience gained from the observation of a large variety of nuclei has made it possible to discuss in a general way the selection of a suitable sample compound. Various interesting phenomena which have turned up in the course of these measurements are discussed; some of these are the following, (a) Nuclear resonance frequencies have been found to depend upon the compound used for the sample in some cases. This has been noted for the isotopes of CI and N, and for Co, the latter having resonances over a region as large as 1.3 percent. This effect has been demonstrated to be of molecular rather than nuclear origin, and it is responsible for our listing the chemical compounds used for each measurement, (b) The magnetic moments of both In 113 and In 115 have been found to be 0.64 percent greater than their respective atomic beam values, a discrepancy very similar to that noted for Ga 69 and Ga 71 . (c) An hfs anomaly for the isotopes of chlorine has been observed, which is notable, because the atomic beam experiments deal with the P3/2 state of atomic chlorine, (d) An unusual structure for the Sb 121 and Sb 123 resonances in aqueous solution of NaSbFe has been observed and is qualitatively explained. * Assisted by the joint program of the AEC and ONR.

A systematic structural modification is carried out to change the molecular shapes of stilbene derivatives from rodlike through hockey stick then to bananalike by tuning the length of the functional group attached to the lateral direction of the rodlike skeletons. The mesophases and the corresponding properties are monitored by optical polarizing microscopy, differential scanning calorimetry, electric field effect, and X-ray diffraction. The existence of mesophase is strongly affected by the molecular conformation and intermolecular forces inherited in the moiety employed. Nematic, smectic C (SmC), and anticlinic smectic C (SmCa) phases are formed by the hockey stick molecules. Defects of 2- and 4-brushes are observed for the SmC and SmCa phases and indicate the existence of anticlinic arrangements of neighboring layers. Anticlinic layer structures constitute the intermediate phases between the calamitic and banana mesophases. Electric-field-switched texture changes are evident for the nematic and SmC phases and are different from those of known calamitic mesogens. These behaviors are ascribed to the bent conformation of these hockey stick molecules. Antiferroelectric B2 banana phases are formed by hockey stick molecules with two arms carrying moieties of large enough polarizability.

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