# $L$-Arginyl-$L$-glutamic Acid Dihydrate, $C_{11}H_{21}N_{5}O_{5}.2H_2O$

Pandit, J and Seshadri, TP and Viswamitra, MA (1983) $L$-Arginyl-$L$-glutamic Acid Dihydrate, $C_{11}H_{21}N_{5}O_{5}.2H_2O$. In: Acta Crystallographica, Section C: Crystal Structure Communications, 39 (12). pp. 1669-1672.

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## Abstract

$M_r = 339.35$, monoclinic, $P2_1$, a = 11.028 (2), b=9.583 (2), $c = 16.010 (2) \AA$, $\beta = 96.57 (1)^0$, $U = 1680.85 \AA^3$, Z = 4, $D_m = 1.37$, $D_x = 1.34 Mg m^{-3}$, $CuK\alpha$, $\lambda = 1.54184 \AA$, $\mu = 0.85 mm^{-1}$, F(000) = 728, T = 300K, R = 0.085 for 2845 diffractometer-measured reflections $[F_0 > 3\sigma(F_0)]$. The two molecules in the asymmetric unit have similar conformations except for a static disorder at the $C^{\beta}$ and $C^{\gamma}$ positions in one of the glutamic-acid side chains. An interesting feature of the crystal structure is a pair of hydrogen bonds between the guanidinium and \gamma-carboxylate groups of neighbouring molecules. This is the first such specific interaction observed between side chains of arginine and glutamic acid.

Item Type: Journal Article Copyright of this article belongs to International Union of Crystallography. Division of Physical & Mathematical Sciences > Physics 08 Jul 2008 19 Sep 2010 04:46 http://eprints.iisc.ernet.in/id/eprint/14647