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Two isostructural carbamates: the o-tolyl N-(pyridin-3-yl)carbamate and 2-bromo-phenyl N-(pyridin-3-yl)carbamate monohydrates.

Mocilac P, Gallagher JF - Acta Crystallogr E Crystallogr Commun (2015)

Bottom Line: The title carbamate monohydrates, C13H12N2O2·H2O and C12H9BrN2O2·H2O, form isomorphous crystals that are isostructural in their primary hydrogen-bonding modes.The remaining water-carbonyl O-H⋯O=C inter-action extends the aggregation into two-dimensional planar sheets that stack parallel to the (100) plane.The Br derivative does not participate in halogen bonding.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Chemical Sciences, Dublin City University, Dublin 9, Ireland.

ABSTRACT
The title carbamate monohydrates, C13H12N2O2·H2O and C12H9BrN2O2·H2O, form isomorphous crystals that are isostructural in their primary hydrogen-bonding modes. In both carbamates, the primary hydrogen bonding and aggregation involves cyclic amide-water-pyridine moieties as (N-H⋯O-H⋯N)2 dimers about inversion centres [as R 4 (4)(14) rings], where the participation of strong hydrogen-bonding donors and acceptors is maximized. The remaining water-carbonyl O-H⋯O=C inter-action extends the aggregation into two-dimensional planar sheets that stack parallel to the (100) plane. The Br derivative does not participate in halogen bonding. A weak intra-molecular C-H⋯O hydrogen bond is observed in each compound.

No MeSH data available.


View of the asymmetric unit of (I)·H2O, showing the atomic numbering schemes. Rotational disorder of the methyl group is depicted. Displacement ellipsoids are drawn at the 30% probability level.
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fig1: View of the asymmetric unit of (I)·H2O, showing the atomic numbering schemes. Rotational disorder of the methyl group is depicted. Displacement ellipsoids are drawn at the 30% probability level.

Mentions: In the CxxOMe series (Mocilac & Gallagher, 2013 ▸), the primary inter­action mode for all nine isomers is the amide⋯pyridine (as N—H⋯N) and typically aggregating as catemers, dimers or trimers. However, there is no evidence for the familiar N—H⋯O=C (amide⋯amide) type hydrogen bonding (Mocilac & Gallagher, 2013 ▸). This is in comparison to a series of related benzamides/carboxamides containing one strong donor/two strong acceptors where competition arises resulting in the formation of either (i) N—H⋯N or (ii) N—H⋯O=C hydrogen bonds as the primary strong inter­action (Mocilac et al., 2010 ▸, 2012 ▸). In the title structures of CmoM (Fig. 1 ▸) and CmoBr (Fig. 2 ▸), the presence of a water mol­ecule in the asymmetric unit was unexpected (water typically assists in the decomposition of organic carbamates at room temperature) though it can be shown to confer additional stability on the structure by forming compact hydrogen bonding and contributing to sheet formation. The retention of carbamate crystal structure integrity is observed over time (as measured in months).


Two isostructural carbamates: the o-tolyl N-(pyridin-3-yl)carbamate and 2-bromo-phenyl N-(pyridin-3-yl)carbamate monohydrates.

Mocilac P, Gallagher JF - Acta Crystallogr E Crystallogr Commun (2015)

View of the asymmetric unit of (I)·H2O, showing the atomic numbering schemes. Rotational disorder of the methyl group is depicted. Displacement ellipsoids are drawn at the 30% probability level.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4645058&req=5

fig1: View of the asymmetric unit of (I)·H2O, showing the atomic numbering schemes. Rotational disorder of the methyl group is depicted. Displacement ellipsoids are drawn at the 30% probability level.
Mentions: In the CxxOMe series (Mocilac & Gallagher, 2013 ▸), the primary inter­action mode for all nine isomers is the amide⋯pyridine (as N—H⋯N) and typically aggregating as catemers, dimers or trimers. However, there is no evidence for the familiar N—H⋯O=C (amide⋯amide) type hydrogen bonding (Mocilac & Gallagher, 2013 ▸). This is in comparison to a series of related benzamides/carboxamides containing one strong donor/two strong acceptors where competition arises resulting in the formation of either (i) N—H⋯N or (ii) N—H⋯O=C hydrogen bonds as the primary strong inter­action (Mocilac et al., 2010 ▸, 2012 ▸). In the title structures of CmoM (Fig. 1 ▸) and CmoBr (Fig. 2 ▸), the presence of a water mol­ecule in the asymmetric unit was unexpected (water typically assists in the decomposition of organic carbamates at room temperature) though it can be shown to confer additional stability on the structure by forming compact hydrogen bonding and contributing to sheet formation. The retention of carbamate crystal structure integrity is observed over time (as measured in months).

Bottom Line: The title carbamate monohydrates, C13H12N2O2·H2O and C12H9BrN2O2·H2O, form isomorphous crystals that are isostructural in their primary hydrogen-bonding modes.The remaining water-carbonyl O-H⋯O=C inter-action extends the aggregation into two-dimensional planar sheets that stack parallel to the (100) plane.The Br derivative does not participate in halogen bonding.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Chemical Sciences, Dublin City University, Dublin 9, Ireland.

ABSTRACT
The title carbamate monohydrates, C13H12N2O2·H2O and C12H9BrN2O2·H2O, form isomorphous crystals that are isostructural in their primary hydrogen-bonding modes. In both carbamates, the primary hydrogen bonding and aggregation involves cyclic amide-water-pyridine moieties as (N-H⋯O-H⋯N)2 dimers about inversion centres [as R 4 (4)(14) rings], where the participation of strong hydrogen-bonding donors and acceptors is maximized. The remaining water-carbonyl O-H⋯O=C inter-action extends the aggregation into two-dimensional planar sheets that stack parallel to the (100) plane. The Br derivative does not participate in halogen bonding. A weak intra-molecular C-H⋯O hydrogen bond is observed in each compound.

No MeSH data available.