A molecular communication channel consisting of a single reversible chain of hydrogen bonds in a conformationally flexible oligomer

•Simple urea oligomers organize themselves with a single coherent hydrogen-bond chain•Reversing the polarity of hydrogen bonding sends message through molecule•Conformational messages can be transmitted by changes in pH or anion binding•Receipt conformational is indicated remote fluorescent response Despite progress made synthetic chemistry building molecular structures nature, there are still domains science where biology immensely more sophisticated than even most advanced artificial chemical systems. One these ability to use encode and communicate information. Nature stores information base pairs translates it into function using matching bonds. Here, we outline an early step toward replicating this design, synthesis, operation series devices that employ structurally simple family oligomeric molecules form polarity. This study marks significant design systems manipulate information, which will basis many compartmentalization-based nanotechnologies future. Communication global switching conformation has hitherto entailed inversion chirality. report class oligomer may communicated reversal Ethylene-bridged oligoureas constitutionally symmetrical, conformationally flexible organized chain bonds running full length oligomer. NMR reveals hydrogen-bonded undergo directionality. The directional uniformity allows act as channel for spatial communication on scale. A binding site at terminus detects local about concentration transmits information—in directionality switch chain—to polarity-sensitive fluorophore. propagation polarity-encoded provides new mechanism communication. general device theorized Claude Shannon 1940s comprises source (input), transmitter (which communicable form), (the medium communicated), receiver (output).1Shannon C.E. mathematical theory communication.Bell Syst. Tech. 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Although spectra sub-ambient temperatures reveal break results methylene signals equal intensity 2B)—a result explained if multiple functions unbroken Coalescence benzylic monourea 1 2B) barrier rotation C–N bond ?G‡298 K = 48.9 kJ mol?1 (from line-shape Eyring analysis: Table S1), ?80 °C, 1H spectrum lies slow-exchange regime. diurea 2a, consisting equally populated singlets low temperature 2B), reasonably correlates breaks timescale. degenerate conformers interconvert 59.4 CD2Cl2. No other conformer evident 2a 2b, indicating no structure, lacking bond, however some extent (about 40% °C) 2c S9), phenyl repel adjacent groups. More chains triurea 3a tetraurea 4a, methylenes occupy identically environments 2B). explanation spectroscopic isoenergetic degenerate) structures. shifts protons CD2Cl2 further support interpretation: slow exchange (?60 upfield (non-hydrogen-bonded) signal 6.65 ppm downfield (hydrogen-bonded) 9.28 S10). 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Binding carboxylic acids ureas.J. 75: 8450-8456Crossref (15) 9.06 9.07 4b) carbonyls after reversal, 9.29 9.81 inductive pyridinium ion. time, 8.8 (a broad resonance clearly resolved °C; S32) moved out consequently 6.29 This, S43 S44), indicates directionality, acting channel, mediating 4bH+ S33) ion donor, inverting triethylamine 4D) returned neutral restored peaks original positions. demonstration wider switching, designed added cation detected sensitive dithiomaleimide fluorophore 7 5A) environment,42Robin M.P. Mabire A.B. Damborsky J.C. Thom E.S. Winzer-Serhan U.H. Raymond J.E. O’Reilly R.K. New handle self-reporting contrast delivery agent nanomedicine.J. 9518-9524Crossref 43Mabire Robin Quan W.D. Willcock Stavros V.G. Aminomaleimide fluorophores: bright, dependent emission.Chem. 51: 9733-9736Crossref 44Robin Wilson P. Kiviaho Haddleton D.M. Conjugation-induced labeling proteins polymers dithiomaleimides.J. 2875-2878Crossref hoped respond decoupling detector raising modular compartmentalized surfaces cells. 8–10 5A, 5E, 5I) synthesized: terminated fluorophore, responsive response. 8a 10, 4b, acid-sensitive: expect protonation alter environment electron-deficient display selectivity anions.34Grayson Scholar,45Gale Caltagirone ensembles.Chem. 44: 4212-4227Crossref experiments S34, S35, S46, S52) indicate compounds upper parts 5I. excitation (emission 523 nm) CH2Cl2 monitored titrated 5B). added, S0-S2 wavelength maximum ?max 358 nm gradually red-shifted 381 equiv, concomitant hyperchromic shift. Minimal spectral observed equiv (?max 1.5 HBF4 384 nm). red band (??max 21 seen longer S47). Under conditions, neither 7a underwent 5C 5D). Additionally, 8b tethered separated maleimide without linking upon S48). confirms when probe hence ionization state dithiomaleimide. result, acceptor (indicated NH: S51), undergoing Next, 530 tetrabutylammonium acetate 5E). involves ureas, weaker donors acceptors (cf. S0-S1 478 blue-shifted 464 5F), moving environment. Bu4NOAc 462 gave minimal 5G 5H). acetate-responsive receiver, responds properties. pH-controlled S55) 5I). Starting repeated sequential (HBF4) (Et3N) successfully four cycles blue-shifted, “neutral” 359 ± 4 red-shifted, “protonated” 386 2 5J). maxima (7a) alone 5K), showing entails seven bonds, causes concerted consecutive summary, synthetically accessible fluxionality, oligureas exhibit feature: sites encoded polarity, demonstrate enables base, ligands) relayed optical properties, repeatable cycles. useful macromolecular analogy hydraulic pressure brake pedal pad) tube.