2-Cyano-anilinium iodide.

The solid-state structure of the title salt, C7H7N2 (+.)I(-), consists of cation-anion sheets lying parallel to (110), with the components linked by N-H⋯I hydrogen bonds.

Microscale visualization of cellular features in adult macaque visual cortex.

Expansion microscopy and light sheet imaging enable fine-scale resolution of intracellular features that comprise neural circuits. Most current techniques visualize sparsely distributed features across whole brains or densely distributed features within individual brain regions. Here, we visualize dense distributions of immunolabeled proteins across early visual cortical areas in adult macaque monkeys. This process may be combined with multiphoton or magnetic resonance imaging to produce multimodal atlases in large, gyrencephalic brains.

4-Cyano-anilinium bromide.

In the crystal structure of the title compound, C(7)H(7)N(2) (+)·Br(-), the cations are associated into inversion dimers through weak pairwise C-H⋯N hydrogen bonds. The dimers further form stepped sheets via weak pairwise C-H⋯N hydrogen bonds. In the sheets, the spacing between the mean planes of the laterally displaced aromatic rings in adjacent dimers is 1.124 (6) Å. Three N-H⋯Br inter-actions and two weak C-H⋯Br inter-actions per cation tie the sheets together.

4-Cyano-anilinium iodide.

In the title compound, C(7)H(7)N(2) (+)·I(-), the cation is located on a site of 4mm symmetry and is thus disordered about the fourfold axis so that there are two perpendicular orientations of the six-membered ring and four rotational orientations of the {-NH(3) (+)} group. In the crystal, there are two layers perpendicular to the c axis, each containing iodide ions and the {-NH(3) (+)} portions of the cations, with the remainder of the cations extending outwards from these layers.

2-Cyano-1-methyl-pyridinium nitrate.

In the title compound, C(7)H(7)N(2) (+)·NO(3) (-), all atoms except the methyl H atoms lie on a crystallographic mirror plane. The inter-layer distance, including that between aligned N atoms from alternating cations and anions in adjacent layers, is exceptionally short at 3.055 (1) Å. Two-dimensional C-H⋯O hydrogen-bonded networks link cations to anions, while C-H⋯N inter-actions link cations within each layer. Anion-π inter-actions with the cations assist in binding the layers together.