Reversible room-temperature ionic liquids

A salt represented by:

• wherein
• R5 represents H, halogen, alkyl, fluoroalkyl, cycloalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heterocycloalkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, —(CH2)n—R8, —OR8, —N(R8)2, —SR8, —C(═O)OR8, —OC(═O)R8, —NR8C(═O)R8, —C(═O)N(R8)2, —C(═O)SR8, —S C(═O)R8, —S(═O)R8, —S(═O)2R8, —S(═O)2OR8, —C(═O)R8, —C(═NR8)R8, —C(═S)R8, —C(R8)═C(R8)2, —C≡CR8, —CH(R8)2, —C(R8)3, or —(CH2)n—NH2;
• R6 represents H, halogen, alkyl, fluoroalkyl, cycloalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heterocycloalkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, —(CH2)n—R8, —OR8, —N(R8)2, —SR8, —C(═O)OR8, —OC(═O)R8, —NR8C(═O)R8, —C(═O)N(R8)2, —C(═O)SR8, —S C(═O)R8, —S(═O)R8, —S(═O)2R8, —S(═O)2OR8, —C(═O)R8, —C(═NR8)R8, —C(═S)R8, —C(R8)═C(R8)2, —C≡CR8, —CH(R8)2, —C(R8)3, or —(CH2)n—NH2;
• Y represents independently for each occurrence O or S;
• R8 represents independently for each occurrence —(CH2)n—CH3, cycloalkyl, aryl, or heteroaryl;
• and
• n represents independently for each occurrence an integer in the range 1-10 inclusive.

A method of preparing a salt, comprising the step of contacting a gas with a first compound and a second compound, wherein said first compound is represented by

• wherein
• R9 is absent or represents one or more substituents attached to the ring, each of which is independently selected from the group consisting of H, halogen, alkyl, fluoroalkyl, cycloalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heterocycloalkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, —(CH2)n—R8, —OR8, —N(R8)2, —SR8, —C(═O)OR8, —OC(═O)R8, —NR8C(═O)R8, —C(═O)N(R8)2, —C(═O)SR8, —S C(═O)R8, —S(═O)R8, —S(═O)2R8, —S(═O)2OR8, —C(═O)R8, —C(═NR8)R8, —C(═S)R8, —C(R8)═C(R8)2, —C≡CR8, —CH(R8)2, —C(R8)3, and —(CH2)n—NH2;
• R8 represents independently for each occurrence —(CH2)n—CH3, cycloalkyl, aryl, or heteroaryl;
• n represents independently for each occurrence an integer in the range 1-10 inclusive;
• z is zero or an integer in the range of 1 to 3;
• and
• said second compound is represented by
• wherein
• R5 represents H, halogen, alkyl, fluoroalkyl, cycloalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heterocycloalkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, —(CH2)n—R8, —OR8, —N(R8)2, —SR8, —C(═O)OR8, —OC(═O)R8, —NR8C(═O)R8, —C(═O)N(R8)2, —C(═O)SR8, —S C(═O)R8, —S(═O)R8, —S(═O)2R8, —S(═O)2OR8, —C(═O)R8, —C(═NR8)R8, —C(═S)R8, —C(R8)═C(R8)2, —C≡CR8, —CH(R8)2, —C(R8)3, or —(CH2)n—NH2;
• R6 represents H, halogen, alkyl, fluoroalkyl, cycloalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heterocycloalkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, —(CH2)n—R8, —OR8, —N(R8)2, —SR8, —C(═O)OR8, —OC(═O)R8, —NR8C(═O)R8, —C(═O)N(R8)2, —C(═O)SR8, —S C(═O)R8, —S(═O)R8, —S(═O)2R8, —S(═O)2OR8, —C(═O)R8, —C(═NR8)R8, —C(═S)R8, —C(R8)═C(R8)2, —C≡CR8, —CH(R8)2, —C(R8)3, or —(CH2)n—NH2;
• R8 represents independently for each occurrence —(CH2)n—CH3, cycloalkyl, aryl, or heteroaryl;
• n represents independently for each occurrence an integer in the range 1-10 inclusive;
• and
• said gas is represented by:
• Y═X═Y
• wherein
• X represents C or N;
• and
• Y represents independently for each occurrence O or S.

A method comprising the step of contacting a first gas with an ionic liquid, thereby generating a second gas;

• wherein said ionic liquid is represented by:
• wherein
• said first gas is an inert gas;
• said second gas is CO2 or CS2;
• R5 represents H, halogen, alkyl, fluoroalkyl, cycloalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heterocycloalkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, —(CH2)n—R8, —OR8, —N(R8)2, —SR8, —C(═O)OR8, —OC(═O)R8, —NR8C(═O)R8, —C(═O)N(R8)2, —C(═O)SR8, —S C(═O)R8, —S(═O)R8, —S(═O)2R8, —S(═O)2OR8, —C(═O)R8, —C(═NR8)R8, —C(═S)R8, —C(R8)═C(R8)2, —C≡CR8, —CH(R8)2, —C(R8)3, or —(CH2)n—NH2;
• R6 represents H, halogen, alkyl, fluoroalkyl, cycloalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heterocycloalkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, —(CH2)n—R8, —OR8, —N(R8)2, —SR8, —C(═O)OR8, —OC(═O)R8, —NR8C(═O)R8, —C(═O)N(R8)2, —C(═O)SR8, —S C(═O)R8, —S(═O)R8, —S(═O)2R8, —S(═O)2OR8, —C(═O)R8, —C(═NR8)R8, —C(═S)R8, —C(R8)═C(R8)2, —C≡CR8, —CH(R8)2, —C(R8)3, or —(CH2)n—NH2;
• X represents C;
• Y represents independently for each occurrence O or S;
• R8 represents independently for each occurrence —(CH2)n—CH3, cycloalkyl, aryl, or heteroaryl;
• R9 is absent or represents one or more substituents attached to the ring, each of which is independently selected from the group consisting of H, halogen, alkyl, fluoroalkyl, cycloalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heterocycloalkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, —(CH2)n—R8, —OR8, —N(R8)2, —SR8, —C(═O)OR8, —OC(═O)R8, —NR8C(═O)R8, —C(═O)N(R8)2, —C(═O)SR8, —S C(═O)R8, —S(═O)R8, —S(═O)2R8, —S(═O)2OR8, —C(═O)R8, —C(═NR8)R8, —C(═S)R8, —C(R8)═C(R8)2, —C≡CR8, —CH(R8)2, —C(R8)3, and —(CH2)n—NH2;
• z is zero or an integer in the range of 1 to 3;
• and
• n represents independently for each occurrence an integer in the range 1-10 inclusive.

A method of removing a gas from a mixture, comprising the step of contacting said mixture with a first compound and a second compound, wherein said first compound is represented by

• wherein
• R9 is absent or represents one or more substituents attached to the ring, each of which is independently selected from the group consisting of H, halogen, alkyl, fluoroalkyl, cycloalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heterocycloalkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, —(CH2)n—R8, —OR8, —N(R8)2, —SR8, —C(═O)OR8, —OC(═O)R8, —NR8C(═O)R8, —C(═O)N(R8)2, —C(═O)SR8, —S C(═O)R8, —S(═O)R8, —S(═O)2R8, —S(═O)2OR8, —C(═O)R8, —C(═NR8)R8, —C(═S)R8, —C(R8)═C(R8)2, —C≡CR8, —CH(R8)2, —C(R8)3, or —(CH2)n—NH2;
• R8 represents independently for each occurrence —(CH2)n—CH3, cycloalkyl, aryl, or heteroaryl;
• n represents independently for each occurrence an integer in the range 1-10 inclusive;
• z is zero or an integer in the range of 1 to 3;
• and
• said second compound is represented by
• wherein
• R5 represents H, halogen, alkyl, fluoroalkyl, cycloalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heterocycloalkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, —(CH2)n—R8, —OR8, —N(R8)2, —SR8, —C(═O)OR8, —OC(═O)R8, —NR8C(═O)R8, —C(═O)N(R8)2, —C(═O)SR8, —S C(═O)R8, —S(═O)R8, —S(═O)2R8, —S(═O)2OR8, —C(═O)R8, —C(═NR8)R8, —C(═S)R8, —C(R8)═C(R8)2, —C≡CR8, —CH(R8)2, —C(R8)3, or —(CH2)n—NH2;
• R6 represents H, halogen, alkyl, fluoroalkyl, cycloalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heterocycloalkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, —(CH2)n—R8, —OR8, —N(R8)2, —SR8, —C(═O)OR8, —OC(═O)R8, —NR8C(═O)R8, —C(═O)N(R8)2, —C(═O)SR8, —S C(═O)R8, —S(═O)R8, —S(═O)2R8, —S(═O)2OR8, —C(═O)R8, —C(═NR8)R8, —C(═S)R8, —C(R8)═C(R8)2, —C≡CR8, —CH(R8)2, —C(R8)3, or —(CH2)n—NH2;
• R8 represents independently for each occurrence cycloalkyl, aryl, or heteroaryl;
• n represents independently for each occurrence an integer in the range 1-10 inclusive;
• and
• said gas is represented by:
• Y═X═Y
• wherein
• X represents C or N;
• and
• Y represents independently for each occurrence O or S.