Chiral metal-dithiolene/viologen ion pairs: synthesis and electrical conductivity.

Enantiomerically pure dithiolene complexes NBu4[Ni[(R,R)-diotte)2] and NBu4[Ni((S,S)-diotte]2] (diotte2- = a 1,3-dioxolane-tetrathiaethylene), were prepared from the corresponding enantiomers of a diotte2- precursor. The structure of the precursor was solved by single-crystal X-ray analysis; desulfurization afforded a novel tetrathiafulvalene derivative. Combination of the complex monoanion with the enantiomers of the viologen derivative bis(2-methyl-3-hydroxypropyl)-4,4'-dipyridinium (HiBV2+) afforded enantiomeric and diastereomeric ion-pair complexes of the type HiBV[Ni(diotte)2]2. For comparison, the analogous compounds A[Ni(diotte)2]2, (A2+ = methyl (MV2+), octyl (OV2-), stearyl (StV2+) viologen or two 2,2'-bipyridinium acceptors), HiBV-[Ni(diotte)L] [L = mnt2- (maleonitrile-1,2-dithiolate), dmit2- (2-thioxo-1,3-dithiol-4,5-dithiolate)], MV[Ni(dmit)2)]2, [Ni(diotte)2], and [Ni(diotte)(dmit)] were synthesized. An X-ray powder diffraction structural analysis of MV-[Ni(dmit)2)]2 revealed the presence of mixed stacks that contain the sequence anion-anion-cation. While no short contacts are observable within a stack, these are observed between the stacks for the dication-anion interaction by short S...H distances in the range of 2.77 to 2.86 A, and for the anion-anion interaction short S...S distances of 3.55 to 3.65 A. In agreement with the absence of intrastack interactions, no ion-pair charge-transfer band can be detected in this and the other complexes. ESR and UV/Vis data suggest that in [Ni(diotte)2]- electron delocalization is less pronounced than in the corresponding mnt2- and dmit2- complexes. The specific electrical conductivity (sigma) of pressed powder pellets ranges from 10(-2) to 10(-12) ohm(-1) cm(-1) and in all cases increases with increasing temperature (293 - 393 K) according to an Arrhenius law. Corresponding activation energies vary from 0.14 to 0.93 eV and increase linearly with log a for structurally similar ion pairs. Charge generation is postulated to occur by disproportionation of the monoanion as suggested by the almost linear increase of log(sigma) with decreasing disproportionation energy. The conductivity of diastereomers of ions with two unlike configurations like [(S,S)-HiBV]-[Ni[(R,R)-diotte]2]2 (1.1 x 10(-1) ohm(-1) cm(-1)) is one to two orders of magnitude higher as compared to the diastereomers with two like-configured ions.

Spouse-aided therapy with agoraphobics.

Sixty agoraphobics were treated by behavioural therapy (self-exposure in vivo) either with their partner involved in all aspects of treatment or without their partner. The two treatment formats were about equally effective. Behavioural treatment directed at the agoraphobia resulted in improvement irrespective of marital quality and partner involvement in the therapy. The effects of treatment led neither to a deterioration of the marriage nor to adjustment problems in the partner. Avoidance behaviour, intropunitivity and overprotection were found to predict treatment response. The partners of agoraphobics were not found to have psychological problems themselves.

Concurrent Cushing's and Zollinger-Ellison syndromes in a patient with islet cell carcinoma. Case report and review of the literature.

This report documents the simultaneous occurrence of Cushing's and Zollinger-Ellison syndromes in a patient with islet cell carcinoma. The clinical concurrence of these two syndromes has been recorded in only three previous case studies, while three other case reports record evidence suggesting the presence of both gastrin and ACTH within the tumor but without clinical sequelae. In the present report, evidence based on multiple clinical and biochemical data supports the concept that both syndromes are a result of "ectopic" hormone production by the tumor.