Hydrogen-Bond Patterns in Several 2:1 Amine-Phenol Cocrystals

N—H.pi(arene) Hydrogen Bonding in 4,4'-Thiodiphenol-Piperazine (1/1)

“…The N---O distance (Table 3) is, as expected, less than the values of 2.821 (3) and 2.867 (3) A observed for the two independent O.-.N distances in the ferrocenediol adduct (Glidewell, Ferguson, Lough & Zakaria, 1994). These values all lie between the values of 2.682 (3) and 3.075 (4),~, observed for the O---H...N and NmH...O hydrogen bonds, respectively, in the phenol adduct (Loehlin, Etter, Gendreau & Cervasio, 1994) the piperazine unit at (x, y, z) acts as a hydrogen-bond donor to the C1-C6 arene ring at (x, -1 + y, z), while the symmetry-related N--H bond in the same piperazine unit acts as donor to the bisphenol at (-x, 1 -y, -z). These interactions thus serve to connect the chains into sheets parallel to the bc plane.…”

“…In the chain-forming 1:1 adduct with ferrocene-1, l'-diylbis(diphenylmethanol), piperazine adopts a chair conformation having one N--H bond axial and the other equatorial; piperazine, however, acts only as an acceptor of hydrogen bonds (O--H...N) and the N--H bonds play no part in the hydrogen-bonding scheme (Glidewell, Ferguson, Lough & Zakaria, 1994). In contrast, in the 2:1 adduct with phenol, 2C6H5OH.CaH10N2, which also forms chains, both N--H bonds are axial in the piperazine units, which have chair conformations, and act as both donors and acceptors of hydrogen bonds, forming N---H...O and O--H...N hydrogen bonds with phenol units (Loehlin, Etter, Gendreau & Cervasio, 1994). As part of a wider study of adduct formation by bisphenols and trisphenols with polyaza acceptors, we have now studied the interaction of bisphenols of type X(C6H4OH)2 (X = O, S, SO2, CO, CMe2) with piperazine.…”

Crystal Engineering Using Tris-phenols. Cross-Linked, Pairwise-Interwoven Two-Dimensional Nets in the 2:1 Adduct of 1,1,1-Tris(4-hydroxyphenyl)ethane with 1,2-Diaminoethane

“…For the major conformer only, the H atoms of the NH2 groups were located from difference maps and these were included in the refinement as riding atoms. In each orientation the N--C--C--N fragment is trans and essentially planar (Table 3); this conformation is similar to those in adducts of the diamine with phenol (Loehlin et aL, 1994) and with 4,4'-biphenol (Ferguson, Glidewell, Gregson, Meehan & Patterson, 1998) and in the diamine itself, where the molecules lie across centres of inversion with no reported disorder at 213 K (JametDelcroix, 1973). However, an electron-diffraction study of 1,2-diaminoethane in the gas phase, i.e.…”

“…Indeed, the values of these bond lengths seem to be rather variable in adducts with phenols: the C--C distance ranges from 1.499 (4) A in (C6H5OH)2.C2HsN2 (Loehlin et at., 1994) to 1.448 (4) * in HOC6HaC t4OH.C2HsN2 (Ferguson, Glidewell, Gregson, Meehan & Patterson, 1998), while the C--N distance varies from 1.494 (4) A in (1) to 1.466 (4) A in (C6HsOH)2.C2HsN2.…”

“…In (1), as well as in [{Mn(CO)3(#3-OH)}n].H2NCH2CH2NH2 (Copp et al, 1992), the diamine acts solely as a bis-acceptor of O-H.. • N hydrogen bonds; in the 2:1 adduct with phenol, (C6HsOH)z.H2NCH2CH2NH2 (Loehlin et al, 1994), and in the methanol-solvated 2:1 adduct with 4,4'-biphenol, (HOC6HaC6HaOH)2.H2NCH2CH2NH2.MeOH (Ferguson, Glidewell, Gregson, Meehan & Patterson, 1998), each nitrogen is both an acceptor and a single donor, while in the 1:1 adduct with 4,4'-biphenol each N atom of the diamine acts as a single donor and double acceptor of hydrogen bonds in a continuous threedimensional diamondoid network (Ferguson, Glidewell, Gregson, Meehan & Patterson, 1998). Only in the 1:1 adduct with 4,4'-biphenol is the idealized complementarity (Ermer & Eling, 1994) of NH2 groups (as double donors and single acceptors of hydrogen bonds) and OH groups (as single donors and double acceptors) apparent.…”