Modeling piperazine thermodynamics

Modeling DNA thermodynamics under torsional stress.

Negatively twisted DNA is essential to many biological functions. Due to torsional stress, duplex DNA can have local, sequence-dependent structural defects. In this work, a thermodynamic model of DNA was built to qualitatively predict the local sequence-dependent mechanical instabilities under torsional stress. The results were compared to both simulation of a coarse-grained model and experimen...

Piperazine-1,4-diium diacetate

In the title salt, C(4)H(12)N(2) (2+)·2C(2)H(3)O(2) (-), the piperazine-1,4-diium cation has 2/m symmetry with the NH(2) unit located on a mirror plane and the acetate anion has m symmetry with all non-H atoms and one H atom located on a mirror plane. The piperazine ring adopts a chair conformation. In the crystal, the cations are linked with the anions via N-H⋯O hydrogen bonding into chains pa...

Tetra­phenyl piperazine-1,4-diyldiphos­pho­nate

The mol-ecule of the title compound, C(28)H(28)N(2)O(6)P(2), is organized around an inversion center located at the centre of the piperazine ring. Both piperazine N atoms are substituted by P(O)(OC(6)H(5))(2) phospho-ester groups. The P atoms display a slightly distorted tetra-hedral environment; the N atoms show some deviation from planarity. The O atoms of the P=O groups are involved in inter...

Piperazine-2,3,5,6-tetra­one. Corrigendum

Piperazine-2,3,5,6-tetra­one

The mol-ecule of the title compound, C(4)H(2)N(2)O(4), is located around an inversion center and the four O atoms are in the 2,3,5,6-positions of the piperazine ring. In the crystal, bifurcated N-H⋯O hydrogen bonds link the mol-ecules into a corrugated layer parallel to (101).