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A series of largely π‐extended multichromophoric molecules including cross‐conjugated, half cross‐conjugated, conjugation‐interrupted and linearly conjugated systems were synthesized and characterized. These multichromophoric molecular systems revealed interesting structural‐property relationships. Bisporphyrin‐fused pentacenesPen‐1 bandPen‐2 ashowed rich redox chemistry with 7 and 8 observable redox states, respectively. The linearly‐conjugated bisporphyrin‐fused pentacenes (Pen‐1 bandPen‐2 a) possess much narrower HOMO–LUMO gaps (1.65 and 1.42 eV redox, respectively) and higher HOMO energy levels than those of their pentacene analogues (2.23 and 2.01 eV redox, respectively), similar to those of much less stable hexacenes and heptacenes. An estimated half‐life of >945 h was obtained for bisporphyrin‐fused pentacenePen‐2 a, which is much longer than that of its pentacene analogue (BPE‐P, half‐life, 33 h).

 

A series of largely π‐extended multichromophoric molecules including cross‐conjugated, half cross‐conjugated, conjugation‐interrupted and linearly conjugated systems were synthesized and characterized. These multichromophoric molecular systems revealed interesting structural‐property relationships. Bisporphyrin‐fused pentacenesPen‐1 bandPen‐2 ashowed rich redox chemistry with 7 and 8 observable redox states, respectively. The linearly‐conjugated bisporphyrin‐fused pentacenes (Pen‐1 bandPen‐2 a) possess much narrower HOMO–LUMO gaps (1.65 and 1.42 eV redox, respectively) and higher HOMO energy levels than those of their pentacene analogues (2.23 and 2.01 eV redox, respectively), similar to those of much less stable hexacenes and heptacenes. An estimated half‐life of >945 h was obtained for bisporphyrin‐fused pentacenePen‐2 a, which is much longer than that of its pentacene analogue (BPE‐P, half‐life, 33 h).

 

The title compound, [Pt(C 4 N 2 S 2 ) 2 (NH 3 ) 2 ], represents an octahedral platinum(IV) complex with two trans- ammine and two mnt (mnt = 1,2-dicyanoethene-1,2-dithiolato) ligands. The Pt—N and Pt—S distances are consistent with those in other platinum(IV) complexes. As a result of a slight canting of the coordination of the mnt ligand to the platinum(IV) atom, the nitrile nitrogen atoms are positioned suitably to hydrogen-bond with adjacent ammines. 

Photoinduced electron transfer (PET) in newly assembled dyads formedviametal‐ligand axial coordination of phenylimidazole‐functionalized bis(styryl)BODIPY (BODIPY(Im)₂) and zinc tetrapyrroles, that is, zinc tetratolylporphyrin (ZnP), zinc tetra‐t‐butyl phthalocyanine (ZnPc) and zinc tetra‐t‐butyl naphthalocyanine (ZnNc), in non‐coordinatingo‐dichlorobenzene (DCB) is investigated using both steady‐state and time‐resolved transient absorption techniques. The structure of the BODIPY(Im)₂was identified by using single crystal X‐ray structural analysis. The newly formed supramolecular dyads were fully characterized by spectroscopic, computational and electrochemical methods. The binding constants measured from optical absorption spectral studies were in the range of ∼10⁴ M⁻¹for the first zinc tetrapyrrole binding and suggested that the two imidazole entities of bis(styryl)BODIPY behave independently in the binding process. The energy level diagram established using spectral and electrochemical studies suggested PET to be thermodynamically unfavorable in the ZnP‐bearing complex while for ZnPc‐ and ZnNc‐bearing complexes such a process is possible when zinc tetrapyrrole is selectively excited. Consequently, occurrence of efficient PET in the latter two dyads was possible to establish from femtosecond transient absorption studies wherein the electron transfer products, that is, the radical cation of zinc tetrapyrrole and the radical anion of BODIPY(Im)₂, was possible to spectrally identify. From target analysis of the transient data, time constants of circa 3 ns for ZnPc^⋅+:BODIPY⋅⁻and circa 0.5 ns for ZnNc⋅⁺:BODIPY⋅⁻were obtained indicating persistence of the radical ion‐pair to some extent. The electron acceptor property of bis(styryl)BODIPY in donor‐acceptor conjugates is borne out from the present study.

 

The re-investigated structure of the title compound, [Cu 2 I 2 (C 12 H 10 N 2 )] n , a two-dimensional coordination polymer crystallizing with monoclinic ( P 2 1 / n ) symmetry, is based on data collected at 100 K, while the previously reported structure was obtained with data collected at 203 K [Blake et al. (1999). Cryst. Eng. 2 , 181–195]. The refinement of the crystal structure is greatly improved; for example, the wR 2 residual converges to 0.047 for 1532 independent data, versus wR 2 = 0.179 for 992 independent data in the 1999 study. 

A fluorous metal–organic framework [Cu(FBTB)(DMF)] (FMOF‐3) [H₂FBTB = 1,4‐bis(1‐H‐tetrazol‐5‐yl)tetrafluorobenzene] and fluorous nonporous coordination polymer [Ag₂(FBTB)] (FN‐PCP‐1) are synthesized and characterized as for their structural, thermal, and textural properties. Together with the corresponding nonfluorinated analogues lc‐[Cu(BTB)(DMF)] and [Ag₂(BTB)], and two known (super)hydrophobic MOFs, FMOF‐1 and ZIF‐8, they have been investigated as low‐dielectric constant (low‐κ) materials under dry and humid conditions. The results show that substitution of hydrogen with fluorine or fluoroalkyl groups on the organic linker imparts higher hydrophobicity and lower polarizability to the overall material. Pellets of FMOF‐1, FMOF‐3, and FN‐PCP‐1 exhibit κ values of 1.63(1), 2.44(3), and 2.57(3) at 2 × 10⁶Hz, respectively, under ambient conditions, versus 2.94(8) and 3.79(1) for lc‐[Cu(BTB)(DMF)] and [Ag₂(BTB)], respectively. Such low‐κ values persist even upon exposure to almost saturated humidity levels. Correcting for the experimental pellet density, the intrinsic κ for FMOF‐1 reaches the remarkably low value of 1.28, the lowest value known to date for a hydrophobic material.

 

A double divergent process has been developed for the reaction of α-enaminones with quinones through facile manipulation of catalyst and additive, leading to structurally completely different products. The two divergent processes, which involve formal aza- and oxo-[3 + 2] cycloaddition reactions, are mediated by chiral phosphoric acid and molecular sieves, respectively. While inclusion of phosphoric acid in the reaction switched the reaction pathway to favor the efficient formation of a wide range of N -substituted indoles, addition of 4 Å molecular sieves to the reaction switched the reaction pathway again, leading to enantioselective synthesis of 2,3-dihydrobenzofurans in excellent yields and enantioselectivities under mild conditions. Studies in this work suggest that the chiral phosphoric acid acts to lower the transition state energy and promote the formation of amide intermediate for the formal aza-[3 + 2] cycloaddition and the molecular sieves serve to facilitate proton transfer for oxo-[3 + 2] cycloaddition. The reactivity of α-enaminones is also disclosed in this work.