Organic Metals: N,N'-Dicyano-1,4-benzoquinonediimines as Acceptors in Charge-Transfer Complexes

ChemInform Abstract: Multistep Reversible Redox Systems. Part 63. 2,5‐Disubstituted N,N′‐Dicyanoquinone Diimines (DCNQIs) — Syntheses and Redox Properties.

“…In connection with the extension of the agreement with the experimental ones given in Table 1. Bond lengths and angles compare well with those of the unsubstituted DCNQI [34] and its 2,5-dimethyl derivative [28] . The crystals of DCNQI 2d belong to the space group Cc in which the molecules are arranged parallel to the b,c plane of the unit cell, the next higher molecule thereby always being placed with its cyano group above the ring of the lower one ( Figure 8, left).…”

2,5-DisubstitutedN, N′-Dicyanoquinone Diimines (DCNQIs) − Syntheses and Redox Properties

“…Figure 8, right. Bond lengths and angles compare well with those of the unsubstituted DCNQI [34] and its 2,5-dimethyl derivative [28] . However, in 2d the C3ϪC4 bond is elongated by 3 pm due to the 5-Semiempirical Calculations for Some DQNQIs methoxy group which even stretches the nitrile bond (C20ϪN21) by 2 pm.…”

“…However, in 2d the C3ϪC4 bond is elongated by 3 pm due to the 5-Semiempirical Calculations for Some DQNQIs methoxy group which even stretches the nitrile bond (C20ϪN21) by 2 pm. The deviation of the two NϪCN In connection with earlier MO calculations for 2,5-disubstituted DCNQIs [33] , AM1 calculations were performed for groups from linearity by 8°corresponds to those in other DCNQIs [28] [34] and indicates slight deviations from the five of the newly snythesized DCNQIs. The newly implemented program package MOPAC 6.0 now contains ideal sp 3 and sp 2 hybridizations, respectively.…”

“…tween the carbonyl oxygen atom of one molecule and the The crystal structure of 2g (R3) represents a third packing type for DCNQIs and related acceptors which until now has not been observed. Both the unsubstituted DCNQI [34] and the 2,5-bis(cyanimino)-2,5-dihydrothieno[3,2-b]thiophene (2,5-Br 2 DCNTT) [39] crystallize in the monoclinic space group P2 1 /c. Both 2,5-Me 2 DCNQI [40] and the aforementioned 2-Cl-5-MeO-DCNQI (2d) (space groups Pnma and Cc respectively) are found with similar arranged molecular layers.…”

N,N'-Dicyano-4,7-indanquinone diimine

“…Among the N,N'-dicyanoquinone diimines as a new class of acceptor molecules, (la) is now the first example to demonstrate this relationship between molecular geometry and electronacceptor properties. While the cyanoimine unit of (la) does not exhibit unusual bond lengths and angles in comparison to other DCNQI derivatives (Andreetti, Bradamante, Bizzari & Pagani, 1985), the whole quinoid system of (la) is expected to have a higher electron affinity than ordinary 2,3-substituted DCNQI's, as a result of the distorted substitution geometry at C3. So (la) readily forms crystalline charge-transfer complexes with electron donors like tetrathiafulvalene (TTF), with a powder conductivity of 3 × 10-3 S cm-t (Metzenthin, 1991).…”