Tatsunari Murakami et al. “Charge-neutral N–H···Br as a hydrogen-bond family for the construction of hydrogen-bonded organic frameworks.” ChemRxiv (). https://doi.org/10.26434/chemrxiv.15002066/v2

Acetone-solvated crystals of bis(benzimidazole)NiBr₂ complex
Identifier 1·(acetone)
Elemental analysis EA calcd (%) for C₂₄H₂₂Br₂N₄NiO: C, 47.97; H, 3.69; N, 9.32, Found: C, 48.19; H, 3.63; N, 9.74
IR (KBr), ṽ (cm⁻¹) 3210br, 1703s (C=O of acetone), 1622m, 1616w, 1531s, 1497m, 1457s, 1393m, 1366m, 1326m, 1283m, 1227m, 1048m, 1005m, 909m, 788m, 737s, 703m, 540m, 499m, 431m
UV/vis (MeCN, r.t.) lmax (nm) (e (M⁻¹·cm⁻¹)) = 526 (88), 569 (sh, 62), 652 (sh, 33)
Main, p. 6
Bis(benzimidazole)NiBr₂ complex formed by storing desolvated complex in air
Identifier 1·(H₂O)₀.₅
Elemental analysis EA calcd (%) for C₂₁H₁₇Br₂N₄NiO₀.₅: C, 45.7; H, 3.11; N, 10.2, Found: C 45.2; H, 2.67; N. 10.2
IR (KBr), ṽ (cm⁻¹) 3265br, 1623m, 1620m, 1532m, 1523m, 1455s, 1388m, 1325m, 1281m, 1230m, 1050w, 1005w, 904w, 744s, 699m, 491m, 424m