H-Phe-Leu-NH2 chloride monohydrate
 A evidence of water-p hydrogen bond with stabilizing energy of 3.26 kcal/mol


Structure of H-Phe-Leu-NH2 Cl H2O (RasMol and POV-Ray3.1)

Ortep drawing here (72 KB)
PDB file and Rasmol script to draw this figure: | Modified PDB | script | @Oct. 2003
O1W-C1G=3.297(2) A
O1W-C1D1=3.305(2) A
O1W-C1E1=3.437(2) A
O1W-C1Z=3.552(2) A
O1W-C1E2=3.512(2) A
O1W-C1D2=3.381(2) A



Geometry around phenyl ring

Paper Hydrogen Bond Between Water and the Phenyl Ring in the Structure of a Dipeptide H-Phe-Leu-NH2 at 90 K and the Structure-Based Energy Estimations.
M. Doi, A. Asano and D. Yamamoto.
Chem. Lett. 32, 1102-1103 (2003).
X-Ray Data Summary
formula C15H23N3O2, HCl, H2O
weight 331.84
symmetrymonoclinic
space group P21
Cell Crystal
a (A) 11.5471(8) description plate
b (A) 6.9111(5) colour Colorless
c (A) 11.7510(8) size (mm) 0.4x0.3x0.08
a (deg) 90 Dx (g/ml) 1.180
b (deg) 95.366(1) F(000) 356
g (deg) 90 m (mm^-1) 0.099
volume 933.7(1) wavelength (A) 0.71073
Z 2
Diffrn measurementRefinementspace
device type Bruker AXS SMART APEX    Flack x parameter -0.06(6)
Rint 0.0161 parameters 207
T (K) 90 restraints 1
q max (deg) 28.27 R_factor_gt 0.0299
reflections obs. 8470 wR_factor_gt 0.0796
reflections for ref. 4118 .gt. 2s(I) Dr max (e/A^3) 0.303
Dr min (e/A^3) -0.181
Structure D/s max 0.001
solutionSHELXS-97 Goodness of fit 0.559
refinementSHELXL-97 fraction for q max  0.956
Get PDB coordinates

Crystal structure
Gaussian UHF/&-31++G(d,p):
SCF Done:  E(UHF) =  -1430.28147620
           A.U. after 50 cycles
           Convg  =    0.3954D-08
           -V/T =  1.9971
           S**2   =   2.0236
Total atomic charges:
 1  Cl    -0.825832
 2  O1W  -0.750256
 3  H1    0.388763
 4  H2    0.369484
 [|Dcharge(H1-H2)| = 0.019279 e]

     
     

     

     Model structures


     
Gaussian UHF/&-31++G(d,p):
SCF Done:  E(UHF) =  -1430.27627294
           A.U. after 45 cycles
           Convg  =    0.4963D-08
           -V/T =  1.9972
           S**2   =   2.0222
Total atomic charges:
 1  Cl     -0.820786
 2  O1W  -0.743027
 3  H1    0.378668
 4  H2    0.383405
 [|Dcharge(H1-H2)| = 0.004737 e]



   Total electron densities of the crystal (left) and model (right) structures. 
   Contours are drawn at the isocharge 0.003 a.u. level. In the model structure (right), 
   the water molecule is rotated 90 deg., and electron cloud is disconneted.
   This means that the orientation of water-hydrogen
   is very important for hydrogen bond. Differencial energy between both models is
   -5.2 x 10^-3 hartrees or -3.26 kcal/mol (1 hartrees = 627.5 kcal/mol).
   











        
    



    

    Hydrogen bonds and coordination to chloride ion
    


      D     H     A    D-H     D...A    H...A  D-H...A   symm. oper.
     N1_1  H3_1  O1W   0.910  2.816(2)  1.945   159.5
     N1_1  H4_1  Cl1   0.910  3.270(1)  2.383   164.9
     N1_1  H5_1  Cl1   0.910  3.229(1)  2.357   160.4  -x+1,+y-1/2,-z+2

     N1_1  H3_1  O1_1  0.910  2.686(2)  2.558    88.1  -x+1,+y-1/2,-z+2
     N1_1  H4_1  O1_1  0.910  2.686(2)  2.645    82.7  -x+1,+y-1/2,-z+2
     N1_1  H5_1  O1_1  0.910  2.686(2)  2.402    98.2  -x+1,+y-1/2,-z+2

     O1W   H1    Cl1   0.881  3.188(1)  2.343   160.9  x,+y-1,+z
     N2T_2 H20_2 Cl1   0.880  3.288(1)  2.440   161.9  -x+1,+y+1/2,-z+2

     O1W   H1    O1_1  0.881  3.087(2)  2.788   101.5  -x+1,+y-1/2,-z+2
     N2_2  H14_2 O2_2  0.880  2.919(2)  2.048   169.9  -x+2,+y-1/2,-z+2
     N2T_2 H19_2 O2_2  0.880  2.915(2)  2.094   154.9  -x+2,+y+1/2,-z+2










Back to the structure index