Fig. 4: Characterization of polyyne rotaxane C48·(Mb)3.
From: Masked alkynes for synthesis of threaded carbon chains
a, Plot showing thermal decomposition of polyyne dumbbell C48 and polyyne rotaxane C48·(Mb)3 in the solid state at 30 °C. Decomposition in the solid state was monitored by dissolving samples of C48 and C48·(Mb)3 in CH2Cl2 and measuring the absorbance at 471 and 480 nm, respectively. Data were fitted to a first-order decay model, A(t) = exp(–kt), with k = 0.011 h–1 and 0.00068 h–1 for C48 and C48·(Mb)3, respectively. b, A partial 13C NMR spectrum of polyyne [4]rotaxane C48·(Mb)3 showing selected sp-carbon chemical shifts (151 MHz, CD2Cl2, 298 K). c, A plot of absorption wavelength of the absorption maximum λmax and Raman shift ν as a function of molecular length in the Mb series fitted to equation (1) gives an λ∞ = 503 nm and v∞ = 1,900 cm–1. The data are listed in Table 1. n is the number of C≡C triple bonds in the polyyne.
