Acridine-based ru-pincer catalysts for reversible hydrogen storage based on ethylene glycol

A compound represented by the structure of Formula (A) or any isomer thereof:

• wherein,
• L1 and L2 is each independently selected from P(alk1)(alk2), P(alk1)(aryl), P(aryl)(aryl), SH, S(alk1), S(aryl), N(alk1)(alk2), NH(alk1), NH(aryl), NH(benzyl), N(alk1)(aryl), and N(aryl)(aryl), wherein alk1, alk2 are each independently substituted or unsubstituted linear or branched C1-C10 alkyl;
• L3 and L4 are each independently absent or a mono-dentate two-electron donor selected from the group consisting of CO, P(R)3, P(OR)3, NO+, As(R)3, Sb(R)3, S(R)2, nitrile (RCN), isonitrile (RNC), ether or cyclic ether;
• and O—, N— or S— heterocycle or heteroaryl, wherein R is selected from the group consisting of alkyl, cycloalkyl, aryl, alkylaryl, heterocyclyl and heteroaryl;
• wherein if L3 is absent then L4 is mono-dentate two-electron donor selected from the above group;
• and wherein if L4 is absent then L3 is mono-dentate two-electron donor selected from the above group;
• Z is H or an anionic ligand selected from the group consisting of halogen, OCOR, OCOCF3, OSO2R, OSO2CF3, CN, OH, OR, N(R)2, RS and SH;
• wherein R is as defined above;
• X1-X3 each independently represents zero, one, two or three substituents selected from the group consisting of alkyl, aryl, halogen, nitro, amide, ester, cyano, alkoxy, cycloalkyl, alkylaryl, heterocyclyl, heteroaryl, an inorganic support and a polymeric moiety.