Synthetic, cyclic voltammetric, structural, EPR, and UV-Vis spectroscopic studies of thienyl-containing meso-A(2)B-cor(Cr(V)=O) systems: consideration of three interrelated molecular detection modalities.

We report eight new A(2)B-type (M(n+)) corrolate compounds (two structural studies) that include the oxo[5,15-bis(pentafluorophenyl)-10-R-corrolatochromium(V)] [R = 2-/3-thienyl (1a/2a), 3-thianaphthyl (3a)] species. The first examples of meso-A(2) (thienyl)- and Cr-A(2)B-corrole types are represented herein. Characterization includes cyclic voltammetry, electron paramagnetic resonance, 2D ((1)H and (13)C) NMR, and UV-vis spectroscopy, mass spectrometry, and elemental analysis. Compounds 1a-3a have enabled analyte binding capacity studies. [Cu(2+)...O=Cr(cor)] binding represents a new selective mode of corrole-based detection, whereas free-base A(2)B-corroles exhibited limited M(n+) selectivity. The 10-position substitution affects optical profiles in analyte titrations. A limited amount of PPh(3) O-atom uptake from [O=Cr(cor)] was also demonstrated.

Optical effects of S-oxidation and M(n+) binding in meso-thienyl dipyrrin systems and of stepwise bromination of 4,4-difluoro-8-(2,5-dibromo-3-thienyl)-4-bora-3a,4a-diaza-s-indacene.

We report 16 novel species and 8 molecular structures in studying how meso-thienyl-substituted dipyrrole oxidation, bromination, and metal ion binding impart optical changes, as monitored by UV-vis absorption/emission spectroscopy. Treatment of 4,4-difluoro-8-(3-benzothienyl)-4-bora-3a,4a-diaza-s-indacene (varphi(F) = 0.19) with m-CPBA gives selective S-dioxidation (varphi(F) = 0.006). Results of titrations of transition metal- and "scorpionate"-like dipyrrin species varied under room temperature treatment of m-CPBA. Ni-(thienyl-dipyrrin)(n) (n = 2) degraded significantly in the presence of m-CPBA, whereas related species (M = Cu, Fe, Co; n = 2, 3) were inert. meso-Thienyl group properties were revealed through the use of 3,4,4-triphenyl-8-(thienyl)-4-bora-3a,4a-diaza-s-indacene; Cu(2+) addition resulted in smooth absorption decreases which were modeled to support 1:1 substrate:M(2+) binding; for Hg(2+) 1:2 substrate:M(2+) binding was found. Treatment of 4,4-difluoro-8-(2,5-dibromo-3-thienyl)-4-bora-3a,4a-diaza-s-indacene with Br(2) gave red-shifted UV-vis absorption band features that grow with increasing dipyrrin bromination. Structures of the di- and tetra-substituted bromination products were obtained.