Self-Associating Curved π-Electronic Systems with Electron-Donating and Hydrogen-Bonding Properties

Abstract

Curved π-electronic molecules, dipyrrolylbenzodiazepines (dpbs), were synthesized via condensation of 1,3-dipyrrolyldiketones and phenylenediamines. Dpbs exhibited 1D hydrogen-bonding chains between pyrrole NH and diazepine N and the resulting packing structures in the solid state. The pyrrole and diazepine N sites coordinate RhI, providing curved π-electronic systems of increasing rigidity. Dpb underwent coassembly with C60, which was surrounded by a hydrogen-bonding ring structure of six dpbs. On photoexcitation, the coassembly exhibited ultrafast electron transfer from the dpb moiety to C60, depending on their proximal arrangement as well as electron-donating and -accepting properties.

Electron-donating curved π-electronic systems that complex with buckyballs

“…On the basis of previous studies, 22 the transient absorption band at B1070 nm can be assigned to the radical anion derived from C 60 . Meanwhile, the band at B965 nm, which was not observed in the single crystal of 1 6 Á C 60 , 7 may be assigned to the radical cation of 2a, as supported by TD-DFT calculations. The evolution-associated spectra were obtained using a three-state sequential kinetic model (Fig.…”

“…13 7,8-Dinitro-2,4-dipyrrol-2-yl-3H-1,5-benzodiazepine, 2b. Following the literature procedure, 7,24 to a propanoic acid solution (1 mL) of 1a 8 (33.8 mg, 0.17 mmol) was added 4,5-dinitro-1,2phenylenediamine 25 (87.9 mg, 0.44 mmol) and the reaction mixture was stirred at 140 1C for 4 h. The solvent was removed and the mixture was washed with CH 2 Cl 2 , Na 2 CO 3 aq. and water and dried over anhydrous Na 2 SO 4 , followed by filtration and evaporation to dryness.…”

“…1 left), a curved π-electronic molecule with multiple hydrogen-bonding sites, has undergone co-assembly with C 60 in the form of a hydrogen-bonding hexamer. 7 Modifications in dpb can provide various C 60 assembled complexes with various electronic properties (Fig. 1 right).…”

Free Charge Carriers in Homo-Sorted π-Stacks of Donor–Acceptor Conjugates

“…Though judicial molecular designing allows control over intermolecular interactions to aid the formation of functional hierarchical structures, a comprehensive understanding of directed emergence of various D–A packing arrangements is still at its infancy. Circumventing the Coulombic interaction directed interdigitating arrangement requires careful engineering of molecular structure and appropriate functionalization of the units. , The π-stacking propensity of D–A units in conjunction with hydrogen bonding, − metal-coordination bonding, − ion templates, − chiral auxiliaries, ,,, self-organizing surface-initiated polymerization, , side-chain functionalization induced amphiphilicity, , and halogen interactions have been utilized to promote segregated D and/or A motifs. Several hierarchical architectures including parallel bicontinuous, coaxial, ,, hexagonal, slip-stacked, helical, ,,, helix wrapped, nonparallel, and alternate distichous possessing segregated arrays have been achieved utilizing such strategies (Figure ).…”

Complexities of the interaction of Ni(II), Pd(II) and Pt(II) pyrrole-imine chelates with human serum albumin

“…[4][5][6] Such ligands are suitable for stabilizing metal ions in both typical and high oxidation states. 7 Examples include crystallographically characterized complexes of Co(II/III), [8][9][10][11] Rh(I/III), [12][13][14][15] Ir(III), 16,17 Ni(II), [18][19][20] Pd(II), [20][21][22] Pt(II), [23][24][25] Cu(II), [26][27][28][29] Ag(I), 30 and Au(III). 31 Pyrrole-based compounds are important building blocks for numerous organic pharmaceuticals, 32 as exemplified by the clinically-approved drugs Tolmetin (a non-steroidal antiinflammatory agent), 33 Sunitinib (multi-targeted receptor tyrosine kinase inhibitor for cancer chemotherapy), 34 and Glimepiride (used to manage type 2 diabetes mellitus by stimulating insulin release), 35 to name a few.…”