Theoretical and Experimental Study of Monofunctional Vinyl Cyclopropanes Bearing Hydrogen Bond Enabling Side Chains

Abstract

The synthesis of four different monofunctional vinyl cyclopropane (VCP) derivatives and their polymerization behavior is presented. The different VCPs have different capabilities to form hydrogen bonds in their side chain. A preorganization due to these hydrogen bonds should lead to a fast polymerization. Kinetic studies, hydrogen-bond strength, and theoretical calculations were used to correlate the degree of conversion and the amount of preorganization. While VCPs capable of hydrogen bonding did not show a huge difference, a general effect of hydrogen bonds on polymerization behavior could be observed.

The Effect of Hydrogen Bonding on Polymerization Behavior of Monofunctional Vinyl Cyclopropane‐Amides with Different Side Chains

“…Although H-bonding influenced the rate of polymerization, the difference among the different functional groups was little, as the hydrogen bonding site was too far from the active site. [13] This finding agrees with a previous report, where the rate of polymerization could be correlated to the distance between hydrogen bond and active site for acrylate monomers. [14] Therefore, we now present a new set of monomers, which bear Hbonding sites at two different positions in VCPs: an amide group linking the sidechain to the cyclopropane ring and different organic functional groups (amide, urethane, and urea) capable of H-bonding to different extents in the side chain to compare their behavior in free-radical photopolymerization concerning the rate of polymerization, and monomer conversion.…”

“…1 H-(300 MHz) and 13 C-nuclear magnetic resonance (NMR) spectra (75 MHz) were recorded on a Bruker Ultrashied-300 spectrometer at room temperature. To distinguish between primary and tertiary or secondary and quarterly carbons, 13 C Attached Proton Test (APT) was conducted.…”

“…1 H-(300 MHz) and 13 C-nuclear magnetic resonance (NMR) spectra (75 MHz) were recorded on a Bruker Ultrashied-300 spectrometer at room temperature. To distinguish between primary and tertiary or secondary and quarterly carbons, 13 C Attached Proton Test (APT) was conducted. The 2-dimensional (2D) NMR heteronuclear single quantum coherence (HSQC) experiments were performed to observe 1 J coupling and Heteronuclear Multiple Bond Correlation (HMBC) experiments for coupling J > 1.…”

“…1 H NMR (300 MHz, CDCl 3 ) 𝛿 8.73 (s, 1H), 6.38 (s, 1H), 5.64 (ddd, J = 17.2, 10.1, 8.8 Hz, 1H), 5.39-5.25 (m, 1H), 5.17 (dd, J = 10.2, 1.4 Hz, 1H), 4.19 (q, J = 7.2 Hz, 2H), 3.55-3.30 (m, 4H), 2.51 (q, J = 8.7 Hz, 1H), 2.20 (q, J = 7.6 Hz, 2H), 2.02 (dd, J = 9.1, 4.3 Hz, 2H), 1.88 (dd, J = 8.0, 4.3 Hz, 1H), 1.28 (t, J = 7.1 Hz, 3H), 1.13 (t, J = 7.6 Hz, 3H). 13…”

Molecular Design of Acrylates Containing Isocyanurate Moiety Undergoing Low Volume Shrinkage during Their Radical Photopolymerization

“…Among 4–6 , the polymerization rate of 6 was faster than those of 4 – 5 and those of 4 and 5 were the same. Recently, Agarwal et al have revealed no effect of hydrogen bonding on the polymerization rate by the comparison of VCP monomers with or without hydrogen bonding . The abovementioned results can be explained from the perspective of the influence of the steric hindrance on the acrylate moiety.…”