288404-65-9Relevant academic research and scientific papers
Syntheses of Acetylenic Oligophenylene Macrocycles Based on a Novel Dewar Benzene Building Block Approach
Ohkita, Masakazu,Ando, Kohta,Suzuki, Takanori,Tsuji, Takashi
, p. 4385 - 4390 (2000)
A general synthetic approach to strained p-phenylene-based acetylenic macrocycles is described. A key feature in this approach is exploitation of Dewar benzene as an angular p-phenylene synthon. Thus, 1,4-acetal-bridged 2,5-dichloro(Dewar benzene) 5, prepared in four steps from dimethyl acetylenedicarboxylate and 1,2-dichloroethylene, is applied as such a building block in the syntheses of strained macrocycles 13 and anti-20. For the synthesis of 13, m-phenylene units are used as spacers and modified Eglington-Glaser coupling is applied for the macrocyclization step. For the synthesis of anti-20, on the other hand, o-phenylene units are used as spacers and Sonogashira coupling is applied for the macrocyclization step. Macrocycles 13 and anti-20 are characterized crystallographically, and their strained nature is reflected mainly in the deviation of the acetylene units from linearity; the C≡C-C angles range from 168.7(3)° to 179.9(3)° in 13 and from 168.0(5)° to 171.4(4)° in anti-20. Macrocycle 13 shows unique conformational property, namely, the p-phenylene units arranged in parallel in the rectangular framework rotate freely about the long axes, as evidenced by the 1H NMR studies. Macrocycle anti-20 exhibits a Stokes shift of 179 nm, which is exceptionally large for phenylacetylene macrocycles, presumably owing to the characteristic stacking structure.
Reversible Multicomponent and Gate Triggered by Stoichiometric Chemical Pulses Commands the Self-Assembly and Actuation of Catalytic Machinery
Biswas, Pronay Kumar,Saha, Suchismita,Gaikwad, Sudhakar,Schmittel, Michael
, p. 7889 - 7897 (2020/05/25)
The present work demonstrates the operation of a reversible supramolecular gate, i.e., an ensemble of various components linked by chemical communication, which is triggered by stoichiometric chemical inputs and by obeying the AND truth table delivers a s
Five-State Rotary Nanoswitch
Gaikwad, Sudhakar,Schmittel, Michael
, p. 343 - 352 (2017/04/26)
In our quest to develop artificial multistate devices, we synthesized the nanomechanical switch 1 that is characterized by a tetrahedral core equipped with four pending arms. The rotary arm with its azaterpyridine terminal is intramolecularly coordinated to a zinc(II) porphyrin station that is the terminus of another arm in 1. The two other arms carry identical sterically shielded phenanthroline stations. The 2-fold alternate addition of a copper(I) ion and [1,10]-phenanthroline (1 equiv each) results in the formation of five different switching states (State I→ State II→ State III→ State IV→ State V → State I), which force the toggling arm to move back and forth between the zinc(II) porphyrin and phenanthroline stations separated by a distance of 25 ?. All switching states constitute clean single species, except for State III, and thus are fully characterized by spectroscopic methods and elemental analysis. Finally, the initial state of nanoswitch was reset by addition of cyclam for complete removal of the copper(I) ions.
