engleski

Conformation and hydrogen bonds in benzyl 1'-carboxy-1-ferrocene-carbamate monohydrate

Helically chiral peptide derivatives of 1'-aminoferrocene-1-carboxylic acid (Fca) was described in our previous work [1, 2]. Fca act as a turn mimetic in oligopeptide derivatives which contains antiparallel peptide strands stabilized by intramolecular hydrogen bonds. Here we present crystal and molecular structure of benzyl 1'-carboxy-1-ferrocene-carbamate monohydrate. Benzyl 1'-carboxy-1-ferrocene-carbamate (N-Cbz-Fca) crystallized with one water molecule in the asymmetric unit. The cyclopentadienyl rings in ferrocenyl moiety adopt an eclipsed conformation. The values of the corresponding C-Cg_1-Cg_2-C pseudo-torsion angles, defined by joining two eclipsing cyclopentadienyl carbon atoms through the ring centroids (Cg), range from -0.26(17) to -0.79(15)^o. The planes of the cyclopentadienyl ring substituents are nearly parallel ; the dihedral angle between the mean planes of the C6/C19/O3/O4 and C1/N1/C11/O1/O2 atoms is 4.39(10)^o. One N-H...O and three O-H...O hydrogen bonds link the molecules of N-Cbz-Fca and water molecules into three-dimensional network. Crystal data: C_19H_19FeNO_5, M_r= 397.20, monoclinic space group P 1 2_1/c 1 (No. 14) ; a=14.5595(4), b=7.5336(2), c=17.3944(5) Å ; , beta=114.484(3)^o ; V = 1736.35(8) Å ; ^3 ; Z=4 ; F(000)=824 ; d_x=1.519 g cm^-3 ; mu=0.899 mm^-1 ; lambda(MoK_alpha)=0.71073 Å ; ; T=295 K ; 4166 independent reflections and 3204 reflections with Ige2sigma(I) used in the refinement ; R = 0.0328 ; R_w=0.0897 ; S=1.060. [1] L. Barišić, M. Dropučić, V. Rapić, H. Pritzkow, S. I. Kirin, N. Metzler-Nolte, Chem. Commun. (2004) 2004-2005. [2] L. Barišić, M. Čakić, K.A. Mahmoud, Y. Liu, H.-B. Kraatz, H. Pritzkow, S. I. Kirin, N. Metzler-Nolte, V. Rapić, Chem. Eur. J. 12 (2006) 4965-4980.

derivatives of 1'-aminoferrocene-1-carboxylic acid; ferrocenyl moiety conformation; hydrogen bonds

nije evidentirano