Dehydrocoupling of the ferrocenylphosphine-borane adducts [FcPH 2 (BH 3 )] (1) [Fc = Fe(C 5 H 5 )(C 5 H 4 )] and [FcCH 2 PH 2 (BH 3 )] (2) with [{Rh(μ-Cl)(cod)} 2 ] (cod = 1,5-cyclooctadiene) as catalyst gave the corresponding phosphorusboron-based polymers [FcPH(BH 2 )] n (3) and [FcCH 2 -PH(BH 2 )] n (4) as low-(heating in toluene, 3 low and 4 low ) or high-molecular-weight (heating without solvent, 3 high or 4 high ) poly(ferrocenylphosphinoborane)s depending on the reaction conditions. Dehydrocoupling of a racemic mixture of [2-N,N-dimethyl(N-borane)aminomethyl-1-ferrocenyl]phosphine-borane (6) resulted in several products, as both BH 3 moieties are apparently involved in polymer formation. Quaternization of the amino group in planar-chiral [Fe(C 5 H 5 ){C 5 H 3 (CH 2 NMe 2 )PH 2 }] (5) with MeI and treatment of the corresponding ammonium salt [Fe(C 5 H 5 )- [a]2457 bond angles at phosphorus vary from 99.6(1) to 115.5(7)°, and those at boron from 102.7(1) to 113.9(2)°.

We report here, the first example of an inorganic-organic hybrid material incorporating a helical iodobismuthate [BiI4]∞ templated by 2,6-diisopropylanilinium cations. The realisation of the helical iodobismuthate opens up the possibility of a wide range of physical properties among hybrid materials.

A systematic approach to obtain bromobismuthates with various bismuth/halide ratios stabilised by 2,6-diisopropylanilinium cations [ArNH 3 ] (Ar = 2,6-diisopropylphenyl) is presented. New bromobismuthate compounds [(ArNH 3 )(BiBr 4 )] ∞ (1), [(ArNH 3 ) 3 (Bi 2 Br 9 )] ∞ (2), [(ArNH 3 ) 3 (BiBr 6 )] (3) and [(ArNH 3 ) 4 -(BiBr 6 )(Br)] (4) with Bi/Br ratios of 1:4, 1:4.5, 1:6 and 1:7 have been isolated and structurally characterised. [Bi 2 Br 9 ] ∞ is a new structural motif in halobismuthate chemistry. In all the com-

Transition-metal-catalyzed dehydrocoupling of tert-butylferrocenylphosphine-borane (2) with [{Rh(μ-Cl)(1,5-cod)}2] (cod = cyclooctadiene) as the catalyst gave the homocoupled product [Fc(tBu)(H)P(BH2)P(Fc)(tBu)(BH2X)] [3; Fc = Fe(C5H5)(C5H4), X = H/Cl], while cross-dehydrocoupling with the tertiary phosphine-boranes P(tBu)(nBu)2(BH3) (2a) and PPh(nBu)2(BH3) (2b) using [Rh(1,5-cod)2]OTf (OTf = trifluoromethanesulfonate) gave the first cross-dehydrocoupled products reported to date, [Fc(tBu)(BH3)P(BH2)P(tBu)(nBu)2] (4) and [Fc(tBu)(BH3)P(BH2)PPh(nBu)2] (5), in moderate yields. Compounds 2-5 were characterized by NMR spectroscopy ((1)H, (13)C, (31)P, and (11)B), IR spectroscopy, mass spectrometry, and single-crystal X-ray structure determination.

Dicarba-closo-dodecaboranes(12) (C2B10H12, carbaboranes) are highly hydrophobic and stable icosahedral carbon-containing boron clusters. The cage framework of these clusters can be modified with a variety of substituents, both at the carbon and at the boron atoms. Substituted carbaboranes are of interest in medicine as boron neutron capture therapy (BNCT) agents or as pharmacophores. High and selective accumulation in tumour cells is an important requirement for a BNCT agent and is achieved by incorporating boron-rich, water-soluble carbaborane derivatives into breast tumour-selective modified neuropeptide Y, [F7, P34]-NPY. Preliminary studies showed that the receptor binding affinity and signal transduction of the boron-modified peptides were very well retained. Use of carbaboranes as pharmacophores was shown by replacement of Bpa32 (Bpa=benzoylphenylalanine) in the reduced-size NPY analogue [Pro30, Nle31, Bpa32, Leu34]-NPY 28–36 by ortho-carbaboranyl propanoic acid. The inclusion of the carbaborane derivative resulted in a short NPY agonist with an interesting hY2R/hY4R preference. This might be a promising approach in the field of anti-obesity drug development.