7,7,8,8-Tetracyanoquinodimethane, ligand

The ternary triazole complex [Fe (abptrz)2(tcnq)2] ((132) in Section 5.4.3.6.3 above abptrz = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole) contains the 7,7, 8,8 -tetracyanoquinodimethane (tcnq) radical anion coordinated in trura-positions at unusually short Fe—N distances the tcnq radical ligands are stacked in pairs to give diamagnetic entities. " ... 

Pal et al. [89] have reported on substituted ferrocenyl compounds, where one of the cyclopentadienyl rings is linked to an aromatic Schiff base, that were synthesized and analyzed for their second-order nonlinearity ((3). Their results indicate that the metal to ligand charge transfer (MLCT) transition dominates their second-order response. These compounds form charge transfer (CT) complexes with acceptors such as Ij, p-chloranil (CA), 2,3-dichloro-5,6-dicyano-l,4-bcnzoquinonc (DDQ), tetracyanoethylene (TCNE), and 7,7,8,8-tetracyanoquinodimethane (TCNQ). The CT complexes exhibit much higher second-order response. Bisferrocenyl complexes where two ferrocene moieties are linked through the same aromatic Schiff base... 

Principal attention in the incorporation of radical multitopic ligands into MOF phases has focused on the well known Tt-acceptors TCNE (tetracya-noethylene) and TCNQ (7,7,8,8-tetracyanoquinodimethane), which in their mononegative forms have an unpaired spin that can couple with... 

Arylation of active methylene compounds has been carried out using Cu salts as promoters under severe conditions [2], Recently it was discovered that the reaction can be carried out much more smoothly using Pd catalysts. The first Pd-catalyzed intermolecular arylation of cyanoacetate and malononitrile with aryl iodides was carried out by Takahashi using PPhs as a ligand, and was applied to a simple synthesis of tetracyanoquinodimethane (2) by the reaction of p-diiodobenzene with malononitrile [3], The intramolecular arylation of malonates and -diketones with aryl iodides proceeds smoothly. Presence of a cyano group seemed to be important [4,5], The arylation has been successfully extended to halides of heterocycles, such as pyridine, quinoline and isoquinoline. The reaction of bromoxazole 3 with sulfone 4 is an example [6]. 

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