A quaternary ammonium compound of formula (I): wherein R.sup.0, R.sup.1, R.sup.2 and R.sup.3 is each independently an optionally substituted hydrocarbyl group; X is a linking group; R.sup.4 is an optionally substituted alkylene group; n is a positive integer; W is O.sup.− or OH; b is 1 when W is OH, and b is 2 when W is O.sup.−. ##STR00001##

A quaternary ammonium compound of formula (I): wherein R.sup.0, R.sup.1, R.sup.2 and R.sup.3 is each independently an optionally substituted hydrocarbyl group; X is a linking group; R.sup.4 is an optionally substituted alkylene group; n is a positive integer; W is O.sup.− or OH; b is 1 when W is OH, and b is 2 when W is O.sup.−. ##STR00001##

A spirobifluorene compound and a perovskite solar cell including the spirobifluorene compound are disclosed. More particularly, a spirobifluorene compound which can be used as a hole transport material of a perovskite solar cell is disclosed. A perovskite solar cell including the spirobifluorene compound as a hole transport material is further disclosed.

A spirobifluorene compound and a perovskite solar cell including the spirobifluorene compound are disclosed. More particularly, a spirobifluorene compound which can be used as a hole transport material of a perovskite solar cell is disclosed. A perovskite solar cell including the spirobifluorene compound as a hole transport material is further disclosed.

Provided are methods to destabilize emulsion feedstocks. In the methods, a moderate temperature is applied to the feedstock to create a first mixture. The moderate temperature may be between 120 and 220 degrees Celsius. The first mixture is mixed at the moderate temperature, such as by staged mixing in some embodiments. Moreover, the first mixture is retained at the moderate temperature for up to six hours. The first mixture is separated into an oil phase, convoluted phase, and a water phase. In some embodiments, the moderate temperature may be 125 to 150 degrees Celsius, such as between 125 and 130 degrees Celsius. Moreover, the first mixture may be retained at the moderate temperature for between forty-five minutes and four hours, such as from two to four hours. The separation may occur at the moderate temperature.

Provided are methods to destabilize emulsion feedstocks. In the methods, a moderate temperature is applied to the feedstock to create a first mixture. The moderate temperature may be between 120 and 220 degrees Celsius. The first mixture is mixed at the moderate temperature, such as by staged mixing in some embodiments. Moreover, the first mixture is retained at the moderate temperature for up to six hours. The first mixture is separated into an oil phase, convoluted phase, and a water phase. In some embodiments, the moderate temperature may be 125 to 150 degrees Celsius, such as between 125 and 130 degrees Celsius. Moreover, the first mixture may be retained at the moderate temperature for between forty-five minutes and four hours, such as from two to four hours. The separation may occur at the moderate temperature.

The present invention provides methods of synthesizing (6S,15S)-3,8,13,18-tetraazaicosane-6,15-diol and salts thereof.

The present invention provides methods of synthesizing (6S,15S)-3,8,13,18-tetraazaicosane-6,15-diol and salts thereof.

A method for producing a nitroso compound of the following formula (3), comprising reacting a compound of the following formula (1) with a compound of the following formula (2) by using a tertiary alcohol and a base. ##STR00001## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, and R.sup.9 are each independently a hydrogen atom, a halogen atom, a (C1-C4) alkyl, or a (C1-C4) alkoxy.

A method for producing a nitroso compound of the following formula (3), comprising reacting a compound of the following formula (1) with a compound of the following formula (2) by using a tertiary alcohol and a base. ##STR00001## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, and R.sup.9 are each independently a hydrogen atom, a halogen atom, a (C1-C4) alkyl, or a (C1-C4) alkoxy.