The Isocyanide Complexes cis-[MCl2(CNC6H4-4-X)2] (M = Pd, Pt; X = Cl, Br) as Tectons in Crystal Engineering Involving Halogen Bonds

Abstract

The isocyanide complexes cis-[MCl2(CNC6H4-4-X)2] (M = Pd; X = Cl, Br; M = Pt; X = Br) form isomorphous crystal structures exhibiting the Cl/Br and Pd/Pt exchanges featuring 1D chains upon crystallisation. Crystal packing is supported by the C–X···X–C halogen bonds (HaBs), C–H···X–C hydrogen bonds (HB), X···M semicoordination, and C···C contacts between the C atoms of aryl isocyanide ligands. The results of DFT calculations and topological analysis indicate that all the above contact types belong to attractive noncovalent interactions. A projection of the electron localization function (ELF) and an inspection of the electron density (ED) and the electrostatic potential (ESP) reveal the amphiphilic nature of X atoms playing the role of HaB donors, HaB and HB acceptors, and a nucleophilic partner in X···M semicoordination.

Stacking Interactions: A Supramolecular Approach to Upgrade Weak Halogen Bond Donors

“… [65] Typically the ED minimum is closer to electrophile nucleus, whereas ESP minimum is closer to nucleophile nucleus, and the area between the two minima corresponds to nucleophile LP. [ 66 , 67 , 68 , 69 , 70 , 71 ] The positions of ED and ESP minima along the X⋅⋅⋅N HaB bond paths confirm the nucleophilicity of N toward X; again, in all studied adducts (Figure 9 ). The same analysis was performed for π‐(C)⋅⋅⋅LP‐(X) interactions, and consideration of the minima positions indicate the nucleophilic properties of X atoms (Figure 10 ).…”

“…Another route to confirm the philicities of noncovalent participants is the analysis of electron density (ED) and electrostatic potential (ESP) distribution along the bond paths [65] . Typically the ED minimum is closer to electrophile nucleus, whereas ESP minimum is closer to nucleophile nucleus, and the area between the two minima corresponds to nucleophile LP [66–71] . The positions of ED and ESP minima along the X⋅⋅⋅N HaB bond paths confirm the nucleophilicity of N toward X; again, in all studied adducts (Figure 9).…”

Metal-Involving Halogen Bonding Including Gold(I) as a Nucleophilic Partner. The Case of Isomorphic Dichloroaurate(I)·Halomethane Cocrystals

“…To the best of our knowledge, this is the first example of the triple exchange of the halomethanes, although the double CHBr 3 /CHCl 3 isostructural isomorphic exchange accompanied by XBs , and not accompanied by XBs and the CHCl 3 /CH 2 Cl 2 isomorphism without XBs have been reported. Previously, we demonstrated the importance of various isostructural exchanges for crystal engineering. ,− Owing to the triple isomorphism in 1 ·CHBr 3 , 1 ·CHCl 3 , and 1 ·CH 2 Cl 2 , the differences in noncovalent interactions in the studied systems are mostly due to the identity of halomethanes.…”

Solid State Phosphorescence Enhancement of PtII-Based Emitters via Combination of π-Hole(Isocyano Group)⋅⋅⋅ dz2[PtII] and I···Cl Halogen-Bonding Interactions

“…The 3D surfaces and 3D visualizations of the NCI plot [75] with an isovalue = 0.35-0.4 and color scale data range of [-0.01; 0.01] were visualized using the VMD 1.9.3 program [76]. ELF projections [77] with the QTAIM method developed by Bader [78][79][80][81] were performed and presented in the Multiwfn 3.8 software [73]. The 1D profiles of the ED/ESP functions [82,83] were calculated in the Multiwfn program.…”