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Interaction of cis,trans,cis-[Rh(H)2(PR3)2(acetone)2]PF6 complexes (R = aryl or R3 = Ph2Me, Ph2Et) under H2 with E-semicarbazones gives the Rh(III)-dihydrido-bis(phosphine)-semicarbazone species cis,trans-[Rh(H)2(PR3)2{R'(R' ')C=N-N(H)CONH2}]PF6, where R' and R' ' are Ph, Et, or Me. The complexes are generally characterized by elemental analysis, 31P{1H} NMR, 1H NMR, and IR spectroscopies, and MS. X-ray analysis of three PPh3 complexes reveals chelation of E-semicarbazones by the imine-N atom and the carbonyl-O atom. In contrast, the corresponding reaction of [Rh(H)2(PPhMe2)2(acetone)2]PF6 with acetophenone semicarbazone gives the ortho-metalated-semicarbazone species cis-[RhH(PPhMe2)2{o-C6H4(Me)C=N-N(H)CONH2}]PF6. The X-ray structure of E-propiophenone semicarbazone is also reported. Rhodium-catalyzed, homogeneous hydrogenation of semicarbazones was not observed even at 40 atm H2.

The effect of a gymnemate salt extract (KGE) on the behavioral and neurophysiological taste responses of Musca domestica to sugar and salt were studied. After exposure of single taste hairs to KGE, the behavioral positive response to a just-suprathreshold sugar stimulus was abolished, and the neuronal firing pattern was modified in a form that ranged from a waxing and waning of impulse frequently to an abolishment of impulses. The neurophysiological response to a salt stimulus was similarly modified, although the waxing and waning of spike frequency was more rapid and firing returned to a near-control pattern sooner. Neurophysiological studies were replicated with two other fly genera. The results uniformly suggest a narcotic effect on the dendrites of taste neurons.