Regular stack, mixed

The dimer energies from Eq. 4 are plotted in Fig. 4 as a function of ionicity, together with AEp for mixed regular stacks. Explicit results for AEct remain approximate for extended systems The relative values of AEp and AEct still yield q approximately, within the dimer picture, for solid CT complexes. In addition, the minimum CT energy probably also occurs for q = /j in Fig. 4, or degenerate D A and DA, in the solid. Torrance and coworkers have effectively exploited the idea of... 

The M2P-TCNQF4 complex could be crystallized, however, and its structure resembles that of TMPD-TCNQ rather than the dimerized M2P-TCNQ stacks in Fig. 11. As shown in Fig. 13, M2P-TCNQF4 forms mixed regular stacks containing planar M2P ions. Inversion centers at each D and A" site ensure equal interaction with both neighbors. The susceptibility, x(T), in Fig. 14 follows the Bonner-Fisher... 

In the regular mixed (rm) stack the only symmetry elements are the inversion symmetry points on which the molecules sit. Each donor or acceptor a mode gives rise to an Ag crystal mode,which is active only in Raman spectra at perturbed frequencies. 

B) Complex radical-ion salts with non-regular stacks (most often mixed-valence dimers or tetramers). The conductivity is higher than for the salts of group A and the activation energy ranges between 0.4 and 0.7 eV examples Cs2(TCNQ)3, b -(7c-llc)2AuBr2 [341]. 

Polyisoprene with regular ingredients was mixed and different mixes containing varied carbon black (0 to 100 phr at the interval of 20) were made. A thin uncured layer of the mix was prepared by pressing it between the mylar sheets in the hydraulic press. The inner surfaces of the mylar sheets were coated with PVA for easy removal of the layer. All these uncured thin layers of different mixes were stacked sequentially with increasing/decreasing amount of carbon black in each layer. The stack as a whole was kept in the mould and compression molded at 150° C for 15 min. in a hydraulic press to get a cured sheet with... 

The intermolecular (interionic) distances must be regular. This "mixed valency" requires that there be only one crystallographically unique molecular site, which must share its partial valency with the nearest neighbor sites along the stack. The many "complex stoichiometry" TCNQ salts—for example, Cs2(TCNQ)32 or triethylammonium(TCNQ)2-, which exhibit "trimeric" or "tetrameric" units of several crystallographically distinct TCNQ molecules and TCNQ- anions held at van der Waals separations—do not conduct well. 

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