The title compound N-(2,4-difluorophenyl)-2-fluorobenzamide (Fo24) was synthesized in high yield (1.09 g; 87%) using standard synthetic procedures from the condensation reaction of 2-fluorobenzoyl chloride with 2,4-difluoroaniline. Crystals of Fo24 were grown from CH2Cl2 at room temperature. The Fo24 crystal structure was determined using single-crystal X-ray diffraction methods at 294 (1) K in space group Pn (No. 7). Fo24 is the second regular tri-fluorinated benzamide with the formula C13H8F3N1O1 to be reported and contrasts with the more common difluorinated and tetra-fluorinated analogues. In Fo24, both aromatic rings are effectively coplanar with an interplanar angle of 0.7(2)°. The central amide group plane is oriented by 23.04(18)° and 23.69(17)° from both aromatic rings, forming an intramolecular contact with an ortho-F12 atom with H1⋯F12 = 2.12(4) Å. The primary hydrogen bonds are 1D amide–amide interactions that form along the b-axis direction. In addition, weaker C-H⋯F/O interactions are noted: a R22(12) synthon involving two C-H, a N-H and two C-F groups, with C-F⋯C ring–ring stacking contacts completing the interactions.

The title compound N-(2,3-difluorophenyl)-2-fluorobenzamide or (Fo23) was obtained at high yield (88%) from the condensation reaction of 2-fluorobenzoyl chloride with 2,3-difluoroaniline using standard synthetic procedures. The crystal structure of Fo23 was determined at 294 (1) K using single crystal X-ray diffraction methods and represents the first regular tri-fluorinated benzamide with formula C13H8F3NO compared to the difluorinated and tetra-fluorinated analogues. In the structure, both aromatic rings are effectively co-planar, with an interplanar angle of 0.5(2)°; however, the central amide group plane is oriented by 23.17(18)° and 23.44(17)° from the aromatic rings as influenced by 1D amide⋯amide hydrogen bonds along the a-axis direction. Longer C-H⋯F/O interactions and the arrangement of a R22(12) synthon involving two C-F, a N-H and two C-H, together with C-F⋯C ring⋯ring stacking contacts, complete the interactions in the Fo23 crystal structure.

A 3 × 3 isomer grid of nine N-(chlorophenyl)pyridinecarboxamides (NxxCl) is reported with physicochemical studies and single crystal structures (Nx = pyridinoyl moiety; xCl = aminochlorobenzene ring; x = para-/meta-/ortho-), as synthesized by the reaction of the substituted p-/m-/o-pyridinecarbonyl chlorides (Nx) with p-/m-/o-aminochlorobenzenes (xCl). Several of the nine NxxCl crystal structures display structural similarities with their halogenated NxxX and methylated NxxM relatives (x = p-/m-/o-substitutions; X = F, Br; M = methyl). Indeed, five of the nine NxxCl crystal structures are isomorphous with their NxxBr analogues as the NpmCl/Br, NpoCl/Br, NmoCl/NmoBr, NopCl/Br, and NooCl/Br pairs. In the NxxCl series, the favored hydrogen bonding mode is aggregation by N-H···Npyridine interactions, though amide···amide intermolecular interactions are noted in NpoCl and NmoCl. For the NoxCl triad, intramolecular N-H···Npyridine interactions influence molecular planarity, whereas NppCl·H2O (as a monohydrate) exhibits O-H···O, N-H···O1W, and O1W-H···N interactions as the primary hydrogen bonding. Analysis of chlorine-containing compounds on the CSD is noted for comparisons. The interaction environments are probed using Hirshfeld surface analysis and contact enrichment studies. The melting temperatures (T m) depend on both the lattice energy and molecular symmetry (Carnelley's rule), and the melting points can be well predicted from a linear regression of the two variables. The relationships of the T m values with the total energy, the electrostatic component, and the strongest hydrogen bond components have been analyzed.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The title compounds, C19H12Br2N2O2 and C18H11Br2N3O2, were synthesized in good yields from condensation reactions of 3-bromo-benzoyl chloride with 2-amino-pyridine or 2-amino-pyrimidine using standard condensation reaction conditions and subsequent column chromatography.

The physicochemical properties of a 3 x 3 isomer grid of mono-chlorobenzamides (Clxx) are reported with comprehensive studies of their crystal structures and interaction environments (Clx = para-/meta-/ortho-chlorobenzoyl and x = para-/meta-/ortho-aminopyridine substitutions). The nine compound Clxx series was synthesized from the three p-/m-/o-chlorobenzoyl chlorides and three p-/m-/o-aminopyridine isomers using standard synthetic procedures. Clxx exhibits some similarities to the related Fxx and Brxx congeners, e.g., the isomorphous behavior of Clpp (para-chloro-N'-(para-pyridyl)benzamide) with several close relatives, and there are five isomorphous pairs of Clxx and Brxx crystal structures. Notably, amp and Clpm both crystallize with Z' = 4 in space group P (1) over bar but show important differences. The overall lack of isomers crystallizing with solvate molecules is noteworthy, except for Clmm center dot(H2O). In all Clxx crystal structures, strong N-H center dot center dot center dot N hydrogen bonds form; however, Clpo also crystallizes as the unexpected Clpo_O polymorph with N-H center dot center dot center dot O=C intermolecular hydrogen bonding. The Clxo triad (with ortho-pyridines) exhibits the expected cyclic N-H center dot center dot center dot N dimer formation with R-2(2)(8) hydrogen bonded rings. The H-C atom type, forming weak C-H center dot center dot center dot Cl hydrogen bonds, is the only favored interaction partner of chlorine in Clxx. Conformational analyses (gas phase) together with crystal contact enrichment studies place Clxx in context and at the interface of hydrogen and halogen bonding interactions, though strong hydrogen bonding dominates. In Clxx, the interaction energies with nearest neighbors are shown to contribute to most of the lattice electrostatic energies. The melting temperatures T-m show correlation with both molecular symmetry (Carnelley's rule) and total electrostatic energy of the weak interactions; in addition, these T-m values can be well predicted from a linear fit combining both descriptors. In Clxx, N-H center dot center dot center dot N hydrogen bonds dominate, largely in the absence of solvates, and with five Clxx forming isomorphous pairs with Brxx analogues, Clpp being isomorphous with several close benzamide relatives. Analysis of T-m reveals correlations involving both symmetry and electrostatic energies.