A family of heterotetrameric clusters of chloride species and halomethanes held by two halogen and two hydrogen bonds

Abstract

Two previously reported 1, 3,5,7,3,6, chloride platinum(II) complexes [PtCl{HN=C(R)N=CN[C(Ph)=C(Ph)]C=NC(R)=NH}] (R = t Bu 1, Ph 2) form solvates with halomethanes 1•1¼CH2Cl2, 1•1⅖CH2Br2, and 2•CHCl3. All these species featuring novel complex-solvent heterotetrameric clusters, where the structural units are linked by simultaneous two C-X•••Cl-Pt (X = Cl, Br) halogen and two C-H•••Cl-Pt hydrogen bonds. The geometric parameters of these weak interactions were determined by single-crystal XRD, and the nature of XB's and HB's in the clusters were studied for the isolated model systems (1)2•(CH2Cl2)2, (1)2•(CH2Br2)2, and (2)2•(CHCl3)2 by DFT calculations and Bader's AIM analysis. The evaluated energies of the weak interactions are in the range 0.9-3.0 kcal/mol. The XB's and HB's in the reported clusters are cooperative. In the cases of (1)2•(CH2Cl2)2 and (1)2•(CH2Br2)2, the contribution of HB's to the stabilization of the system is dominant, whereas for (2)2•(CHCl3)2 contributions of both types of non-covalent interactions are almost the same. Crystal packing and other forces such as, e.g. dipole-dipole interactions, also affect the formation of the clusters.

Diiodomethane as a halogen bond donor toward metal-bound halides

“…This approach has already been successfully used by our group in studies of different non-covalent interactions (e.g., hydrogen, halogen and chalcogen bonding, metallophilic interactions, stacking) and properties of coordination bonds in various transition metal complexes. 17,22,[55][56][57][58][59][60][61] The contour line diagrams of the Laplacian distribution ∇ 2 ρ(r), bond paths, and selected zeroflux surfaces for intermolecular H⋯Cl HBs and I⋯Cl XBs are shown in Fig. 11.…”

“…The low magnitude of the electron density (0.011-0.013 Hartrees), positive values of the Laplacian (0.037-0.041 Hartrees), and close-to-zero positive energy density (0.001 Hartrees) in these BCPs are typical for both HB and XB. 17,22,65,66 We have defined energies for these contacts according to the procedures proposed by Espinosa et al 63 and…”

“…1) are still able to form supramolecular clusters with chloride anions and chloride ligands in metal complexes held by XBs and HBs 16,21,22 or by simultaneous XB and HB. 16,21,22 In contrast to a rather broad application of halomethanes in crystal engineering, diiodomethane (CH 2 I 2 ) -despite its relatively large σ-holes ( Fig. 1; positive potential is up to 23.1 kcal mol −1 on the 0.001 a.u.…”

“…[11][12][13][14][15][16][17][18][19][20] Concurrently, halide complexes of d-metals can be employed as XB acceptors and their combination with halomethanes leads to supramolecular clusters, chains, and 3D networks. 17,18,[20][21][22] The halomethanes CBr 4 , [11][12][13][18][19][20] CHI 3 , 14,15,17,23 CHBr 3 , 11,12,20 and CFBr 3 12,19 are the most commonly used among other halomethanes in the formation of XBs with uncomplexed halides and polyhalometalate anions. Our recent works indicated that even weak XB donors such as CHCl 3 , CH 2 Cl 2 , and CH 2 Br 2 ( Fig.…”

Intra-/Intermolecular Bifurcated Chalcogen Bonding in Crystal Structure of Thiazole/Thiadiazole Derived Binuclear (Diaminocarbene)PdII Complexes

“…These results are accordingly discussed in the sections that follow. In the continuation of our projects focused on metal-mediated reactions of isocyanides [15,[58][59][60][61][62][63][64][65][66][67][68] and on non-covalent interactions [15,58,[69][70][71][72][73][74][75][76][77], we recently reported on the coupling between cis-[PdCl 2 (CNXyl) 2 ] (Xyl = 2,6-Me 2 C 6 H 4 ) and various thiazol-and thiadiazol-2-amines that leads to a mixture of two regioisomeric binuclear diaminocarbene complexes corresponding to kinetically (3a-d) or thermodynamically (4a-d) controlled regioisomers (Scheme 1). There is an equilibrium between these two species in CHCl 3 solutions that depends on the energy difference between two types of intramolecular CBs, viz.…”