110352-20-0

Upstream product

• 86534-12-5 (±)-2,7,12-trimethoxy-3,8,13-tris(2-propenyloxy)-10,15-dihydro-5Htribenzo[a,d,g]cyclononene 
• 498-00-0 4-hydroxymethyl-2-methoxyphenol 
• 110316-15-9 [4-(3-{7,12-Bis-[3-(4-hydroxymethyl-2-methoxy-phenoxy)-propoxy]-3,8,13-trimethoxy-10,15-dihydro-5H-tribenzo[a,d,g]cyclononen-2-yloxy}-propoxy)-3-methoxy-phenyl]-methanol 
• 110316-15-9 [4-(3-{7,12-Bis-[3-(4-hydroxymethyl-2-methoxy-phenoxy)-propoxy]-3,8,13-trimethoxy-10,15-dihydro-5H-tribenzo[a,d,g]cyclononen-2-yloxy}-propoxy)-3-methoxy-phenyl]-methanol 
• 110316-11-5 4-(3-bromopropoxy)-3-methoxyphenyl methanol 
• 110316-10-4 4-(3-iodopropoxy)-3-methoxybenzenemethanol 
• 81370-49-2 cyclotriguaiacyclene 
• 110316-12-6 1,3-bis<4-(hydroxymethyl)-2-methoxyphenoxy>propane 

Relevant academic research and scientific papers

Spectral study on the inclusion complex of cryptophane-E and CHCl3

Cryptophane-E was synthesized from vanillin by a three-step method, and its absorption and fluorescence spectroscopic properties were determined. Two absorption bands at about 245-260 and 280-290 nm were observed for cryptophane-E and the fluorescence emission maxima were at 320-330 nm depending on the solvent used. The interaction of cryptophane-E with CHCl3 was studied in detail by absorption and fluorescence spectroscopies. The results showed that cryptophane-E and CHCl3 can easily form a stable 1:1 host-guest inclusion complex. Their binding constant (K) was determined by Benesi-Hildebrand equation and the nonlinear least squares fit method. The binding constant is largest in ethyl acetate, followed by dioxane and with acetonitrile as the smallest. In addition, the effect of guest volume on the host-guest inclusion complex was investigated. Guest molecules including CH2Cl2 and CCl4 were unable to form inclusion complex with cryptophane-E because of sizes mismatching with the host cavity.

Improved synthesis of functional CTVs and cryptophanes using Sc(OTf) 3 as catalyst

Functional cyclotriveratrylene (CTV) and cryptophane derivatives are synthesized in the presence of scandium triflate [Sc(OTf)3]. This route allows the preparation of new derivatives that could not be prepared or easily obtained by using the previously reported experimental procedures. With a catalytic amount of scandium triflate (1% mol), CTVs were obtained with yields similar to or higher than those reported previously in reactions run under strong acidic conditions. Cryptophanes were also synthesized in fairly good yields by performing the ring-closure step in the presence of a stoichiometric amount of Sc(OTf)3. Interestingly, this novel approach strongly reduces the formation of side products and gives rise to novel functionalized molecules for the construction of supramolecular host-guest systems.

Two-step synthesis of D3 and C3h cryptophanes

Dihalides X-(Z)-X, [Z = (CH2)n; n = 1-7 or CH 2CH=CHCH2] react with the phenol group of vanillyl alcohol to give the dialkylated derivatives HOCH2-Ar-O-(Z)-O-Ar-CH 2OH (2), which in turn, in the presence of formic acid, afford the corresponding D3 cryptophanes (3), with, in some cases, minor amounts of the C3h isomers (4).

Synthesis and Exciton Optical Activity of D3-Cryptophanes

Six optically active D3-cryptophanes (1-6) have been synthesized and thei absolute configurations established unambiguously.In order to explain their circular dichroism (CD) spectra, a simple theoretical model, based on the Kuhn-Kirkwood excition mechanism, has been developed for the coupling of six equivalent oscillators in a D3 molecular point group.The model predicts for each B2u and B1u benzene transition the presence of three CD components, one (A2) being polarized along the C3 axis and two (E) in the plane containing the C2 axes.The two E components have opposite signs and different intensities, the stronger having sign opposite to the A2 transition.The splitting between the E states in each band system is dependent on the twist angle (2γ) between the upper and the lower caps of the molecule.For 2γ = 60 deg (staggered conformation), this splitting is estimated to be very small, compared to the corresponding E - A2 energy difference, and the E components are never resolved in the theoretical plotted spectra for any realistic bandwith.For 2γ = 0 deg (eclipsed conformation), the calculated splitting of the E states is large enough to become apparent in plotted spectra for the B1u system.When a staggered conformation is assumed, the experimental CD spectra of cryptophanes 1-6 have been, in most cases, satisfactorily interpreted in terms of the model, with the polarization direction of the transitions set in accordance to the spectroscopic moment theory by using the rules previouly established for C3-cyclotriveratrylenes.In some cases, the energy sequence of the E states for the B2u system is not agreement with the predictions, probably due to the failure of the point-dipole approximation to determine the exact sequence of almost degenerate states.The results of this study point out the importance of the coupled-oscillator model in explaining the CD spectra of complex molecules containing more than three oscillators.