Different Stacking Types in a Single Hybrid Cocrystal System: π···π- and π-Hole-Based Organic-Inorganic Planar Assemblies.

The planar bis-chelated complex [Pd(NO)] (; NO = 4-MeCHNNC(O)NMe) exhibits two distinct stacking modes with electron-deficient aromatics: π···π stacking with hexafluorobenzene (CF) versus charge-transfer π-hole interactions with 1,2,4,5-tetracyanobenzene (TCB). Cocrystallization of the complex with CF or TCB yields cocrystals ·3(CF) and ·2TCB, respectively, which display different colors and stacking patterns despite similar structural motifs. Comprehensive analysis using X-ray diffraction, combined with quantum theory of atoms-in-molecules (QTAIM), an independent gradient model based on Hirshfeld partition (IGMH), extended transition state natural orbital for chemical valence theory with charge displacement function (ETS-NOCV/CDF), many-body interaction analysis, and symmetry-adapted perturbation theory (SAPT), reveals fundamentally different interaction mechanisms.

Nucleophilicity of the Nitrile N Atom Whose Lone Pair Is Blocked by Metal Coordination. The π-Hole Interaction between an Arene Carbon and the Metal-Bound Nitrile Nitrogen.

Cocrystallization of CuI with NCNMe in the presence of substituted perfluoroarenes─iodoperfluorobenzene (IFB), 4,4'-diiodoperfluorobiphenyl (4,4'-FIBP), and 4-bromoperfluorobenzonitrile (4-BrFBN)─led to the formation of three types of adducts ·2(IFB), ·4,4'FIBP, and ·4-BrFBN ( is CuI(NCNMe)), all studied by X-ray crystallography. In these cocrystals, the coordinated nitrile N atom (whose electron pair is engaged in metal coordination) still acts as an electron donor, forming π-hole interactions, specifically, π-hole···N, with the perfluoroarenes. These interactions were examined in the context of their occurrence alongside other interactions involving C atoms of the electron-deficient aromatic rings and nucleophilic atoms of the copper cluster.

When a Side Reaction Is a Benefit: A Catalyst-Free Route to Obtain High-Molecular Cobaltocenium-Functionalized Polysiloxanes by Hydroamination.

Cobaltocenium-containing (co)polysiloxanes (Cc-PDMSs) with terminal and side groups were synthesized by the reaction of catalyst-free hydroamination between ethynylcobaltocenium hexafluorophosphate and polysiloxanes comprising amino moieties as terminal and side groups. The conversion of NH groups in the polymers reaches 85%. The obtained (co)polysiloxanes "gelate" due to an increase in their molecular weight by approx.

Intermolecular Metal-Involving Pnictogen Bonding: The Case of σ-(Sb)-Hole···d[Pt] Interaction.

Cocrystallizations of -[PtX'(NCNR)] (R = Me, X' = Cl , Br , I ; R = (CH), X' = I ) with SbX (X = Cl, Br, I) gave 1:2 cocrystals ·2SbCl, ·2SbBr, ·2SbCl, ·2SbBr, ·2SbI, and ·2SbI. In all six X-ray structures, the association of the molecular coformers is achieved mainly by Sb···d[Pt] metal-involving intermolecular pnictogen bonding. Density functional theory (DFT) calculations (based on experimentally determined geometries) using both gas-phase and solid-state approximations revealed that a σ-(Sb)-hole interacts with an area of negative potential associated with the d-orbital of the positively charged platinum(II) sites, thus forming a pnictogen bond whose energy falls in the range between -7.

Metal-Induced Enhancement of Tetrel Bonding. The Case of C⋅⋅⋅X-Ir (X=Cl, Br) Tetrel Bond Involving a Methyl Group.

In X-ray structures of the isomorphic mer-[IrX(THT)(CNXyl)] (X=Cl 1, Br 2; THT=tetrahydrothiophene; Xyl=2,6-MeCH-) complexes, we revealed short intermolecular contacts between the C-atom of an isocyanide methyl group and halide ligands of another molecule. Geometrical consideration of the X-ray data and analysis of appropriate DFT studies allowed the attribution of these contacts to C⋅⋅⋅X-Ir (X=Cl, Br) tetrel bond. Specifically, through the application of DFT calculations and various theoretical models, the presence of tetrel bonding interactions was validated, and the contribution of the C⋅⋅⋅X-Ir interaction was assessed.