Domon, M. et al. published their research in Molecular Crystals and Liquid Crystals in 1987 | CAS: 39969-26-1

1-Methoxy-4-((4-propylphenyl)ethynyl)benzene (cas: 39969-26-1) belongs to ethers. Ether is less polar than esters, alcohols or amines because of the oxygen atom that is unable to participate in hydrogen bonding due to the presence of bulky alkyl groups on both sides of the oxygen atom. But ether is more polar than alkenes. Autoxidation is the spontaneous oxidation of a compound in air. In the presence of oxygen, ethers slowly autoxidize to form hydroperoxides and dialkyl peroxides. If concentrated or heated, these peroxides may explode. To prevent such explosions, ethers should be obtained in small quantities, kept in tightly sealed containers, and used promptly.Reference of 39969-26-1

New methods for calculating the temperatures and the enthalpy changes of virtual transitions and predicting phase diagrams – applied to the tolans was written by Domon, M.;Buisine, J. M.. And the article was included in Molecular Crystals and Liquid Crystals in 1987.Reference of 39969-26-1 This article mentions the following:

For a mesogen which does not exhibit an enantiotropic nematic phase when pure, 2 methods are proposed for the determination of the temperatures and enthalpy changes of the nematic-isotropic liquid virtual transitions. These calculations, based on Schroeder-van Laar and van Laar equations, use the value of the liquid appearance temperature for mixtures of the compound with another mesogen which exhibits the enantiotropic mesophase when pure. Both methods are applied to the study of the 1st 10 compounds in the 4-methoxy-4′-alkyltolan series. The results are used to determine the eutectic, liquid appearance and nematic disappearance temperatures of mixtures of 2 tolans that do not exhibit an enantiotropic nematic phase when pure. In 7 cases, an enantiotropic nematic phase is predicted and observed; in 1 case, the phase diagram differs from that expected; for the remainder, the calculated and exptl. data agree. In the experiment, the researchers used many compounds, for example, 1-Methoxy-4-((4-propylphenyl)ethynyl)benzene (cas: 39969-26-1Reference of 39969-26-1).

1-Methoxy-4-((4-propylphenyl)ethynyl)benzene (cas: 39969-26-1) belongs to ethers. Ether is less polar than esters, alcohols or amines because of the oxygen atom that is unable to participate in hydrogen bonding due to the presence of bulky alkyl groups on both sides of the oxygen atom. But ether is more polar than alkenes. Autoxidation is the spontaneous oxidation of a compound in air. In the presence of oxygen, ethers slowly autoxidize to form hydroperoxides and dialkyl peroxides. If concentrated or heated, these peroxides may explode. To prevent such explosions, ethers should be obtained in small quantities, kept in tightly sealed containers, and used promptly.Reference of 39969-26-1

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem