Structure of di(S-methylthiouronium)–tri(7,7,8,8-tetracyano-p-quinodimethane) dihydrate, (MT)2(TCNQ)3.2H2O

Semiconductive 2D arrays of pancake-bonded oligomers of partially charged TCNQ radicals

“…Thus, the total charge of a trimer is À1.72, fairly close to the formal value of À2. Similar values have been found for similar trimers (Usov et al, 1991). A more reliable assessment of total charge based on X-ray charge density was recently used in a study of a trimer of tetrachlorosemiquinone radicals with a formal charge of À2 (Molc ˇanov et al, 2018b), and it revealed similarly uneven distribution of the negative charge: the central ring has a higher total charge of À0.76, whereas the two lateral rings have a charge of À0.59.…”

“…charge derived from stoichiometry) of TCNQ is À1/2 (Ashwell et al, 1977a(Ashwell et al, , 1982. Pancake-bonded trimers, which often form stacks, are quite common, with a formal charge on the TCNQ À moiety of À2/3 (Ashwell et al, 1977b;Endres et al, 1978a,b;Ashwell & Wallwork, 1979; Sandman et Lau et al, 1982;Bell et al, 1991;Usov et al, 1991;Akutagawa et al, 1996Akutagawa et al, , 2004Bigoli et al, 1996;Ballester et al, 2000;Nishijo et al, 2004;Chen et al, 2007;Liu et al, 2008;Mochida et al, 2008;Martin et al, 2012;Kubota et al, 2014;Phan et al, 2015). However, different bond lengths in the central and lateral rings of a trimer indicate different total charge of the rings, which can be estimated using geometric correlations (see above).…”

“…However, different bond lengths in the central and lateral rings of a trimer indicate different total charge of the rings, which can be estimated using geometric correlations (see above). For example, in the compound (MT) 2 (TCNQ) 3 Á2H 2 O (MT = S-methilthiouronium) the charges on the central ring and the lateral rings were estimated to be À0.9 and À0.4, respectively; the total charge of a trimer is thus À1.7 (Usov et al, 1991). In a 2:3 salt of N,Ndimethyl-d-proline-methylester and TCNQ À the rings form a trimer stack in the sequence ...ABB... with the charge of A being À0.30 and of B being À0.94 [thus, the charge of the trimer is À2.18 (Martin et al, 2012)].…”

Hydrogen-Bonded Networks in Organic Conductors: Crystal Structures and Electronic Properties of Charge-Transfer Salts of Tetracyanoquinodimethane with 4,4‘-Biimidazolium Having Multiprotonated States

“…As for the anionic part, TCNQ radical anions have played a central role from an early stage of the research for molecular conductors in the 1960s . Despite a variety of TCNQ salts with ammonium-type cations as H-bonded CT salts being examined, very few works have been reported to address the salts showing high conductivities with multidimensional H-bonded networks between TCNQ and cationic moieties. , Therefore, further development is required to design more suitable counterions with sufficient H-bonding ability having robust directionality and to build up highly ordered multidimensional network based on H-bonded TCNQ salts.…”

(2-Bromoethyl)trimethylammonium bromide and thiourea: A comparative study of three crystal structures

“…For chemically related structures values ranging from 1.727 to 1.752 for the shorter and from 1.785 to 1.858 Å for the longer carbon-sulfur bond have been reported [33][34][35][36][37]. Fig.…”