Crystallographic and computational study of a network composed of [ZnCl₄]²⁻ anions and triply protonated 4′-functionalized terpyridine cations

Abstract

We report herein the synthesis, crystallographic analysis and a study of the noncovalent interactions observed in the new 4'-substituted terpyridine-based derivative bis[4'-(isoquinolin-2-ium-4-yl)-2,2':6',2''-terpyridine-1,1''-diium] tris[tetrachloridozincate(II)] monohydrate, (CHN)[ZnCl]·HO or (ITPH)[ZnCl]·HO, where (ITPH) is the triply protonated cation derived from 4'-(isoquinolin-4-yl)-2,2':6',2''-terpyridine (ITP) [Granifo et al. (2016). Acta Cryst. C72, 932-938]. The (ITPH) cation presents a number of interesting similarities and differences compared with its neutral ITP relative, mainly in the role fulfilled in the packing arrangement by the profuse set of D-H...A [D (donor) = C, N or O; A (acceptor) = O or Cl], π-π and anion...π noncovalent interactions present. We discuss these interactions in two different complementary ways, viz. using a point-to-point approach in the light of Bader's theory of Atoms In Molecules (AIM), analyzing the individual significance of each interaction, and in a more `global' analysis, making use of the Hirshfeld surfaces and the associated enrichment ratio (ER) approach, evaluating the surprisingly large co-operative effect of the superabundant weaker contacts.

Single-Crystal-to-Single-Crystal Transformation and Catalytic Properties of New Hybrid Perhalidometallates

“…S2). These geometry parameters are in the same magnitude as those observed in homologous compounds containing isolated anions [ZnCl4] 2− [33][34][35][36][37].…”

“…In the anion, the Zn II atom is coordinated by four Cl atoms in a slightly distorted tetrahedral geometry (τ 4 = 0.95), with Zn-Cl bond lengths ranging from 2.262 (2) Å to 2.282 (18) Å, and the Cl-Zn-Cl bond angles varying between 106.33 (7) • and 114.22 (8) • (Table S2). These geometry parameters are in the same magnitude as those observed in homologous compounds containing isolated anions [ZnCl 4 ] 2− [33][34][35][36][37].…”

“…In the anion, the Zn II atom is coordinated by four Cl atoms in a slightly distorted tetrahedral geometry (τ4 = 0.95), with Zn-Cl bond lengths ranging from 2.262 (2) Å to 2.282 (18) Å , and the Cl-Zn-Cl bond angles varying between 106.33 (7)° and 114.22 (8)° (TableS2). These geometry parameters are in the same magnitude as those observed in homologous compounds containing isolated anions [ZnCl4] 2−[33][34][35][36][37].The cyclohexane ring shows a chair conformation and has been modelled as disordered over two positions at half occupancy. C2 and C5 belong to both rings and have been refined at full occupancy.…”

The enrichment ratio of atomic contacts in the crystal structure of isomeric, triply protonated, 4′-functionalized terpyridine cations with [ZnCl4]2− as counter-ion

“…We have recently reported the use of the 4 0 -pyridyl-substituted terpyridine 4 0 -(isoquinolin-4-yl)-2,2 0 :6 0 ,2 00 -terpyridine (22TP) in the synthesis of the tetrachloridozincate salt (22TPH 3 ) 2 [ZnCl 4 ] 3 ÁH 2 O (II) containing the triply protonated cation (22TPH 3 ) 3+ (Granifo et al, 2017). The structural study of (II) demonstrates the concerted way in which a series of non-covalent interactions, viz.…”