108
A. Bagaria and S. Ramakumar
Table 4 Crystallographic details of dipeptide II (VF)
Empirical formula
(C14 H17 N2 O3)2. 2H2O
Molecular weight
262.308
Crystal system
Monoclinic
Space group
C 2
Cell parameters
a = 31.0101(62) Å, b = 5.5658(11) Å, c = 18.8130(38) Å, β =
115.43(30)˚
Cell volume
2932.57(463) Å 3
Z
8
Density calculated
1.18 gm cm −3
Absorption coefficient
0.084 mm −1
Radiation used
Mo (λ = 0.71073 Å)
Resolution
0.9 Å
Unique reflections
3085
Observed reflections
2949 (|Fo| > 4 σ (|Fo|))
Structure solution
Shelxs
Refinement procedure
Full-matrix least-square refinement on |Fo| 2 using Shelxl (972)
No: of parameters refined 360
Data/parameter
8.2
R-factor
4.63%
wR2
13.16%
GooF (s)
1.044
Residual electron density Max. = 0.49e/Å 3 , Min. = −0.18 e/Å 3
Fig. 10 Conformation of peptide II (VF) with residue labelling
A. Bagaria and S. Ramakumar
Table 4 Crystallographic details of dipeptide II (VF)
Empirical formula
(C14 H17 N2 O3)2. 2H2O
Molecular weight
262.308
Crystal system
Monoclinic
Space group
C 2
Cell parameters
a = 31.0101(62) Å, b = 5.5658(11) Å, c = 18.8130(38) Å, β =
115.43(30)˚
Cell volume
2932.57(463) Å 3
Z
8
Density calculated
1.18 gm cm −3
Absorption coefficient
0.084 mm −1
Radiation used
Mo (λ = 0.71073 Å)
Resolution
0.9 Å
Unique reflections
3085
Observed reflections
2949 (|Fo| > 4 σ (|Fo|))
Structure solution
Shelxs
Refinement procedure
Full-matrix least-square refinement on |Fo| 2 using Shelxl (972)
No: of parameters refined 360
Data/parameter
8.2
R-factor
4.63%
wR2
13.16%
GooF (s)
1.044
Residual electron density Max. = 0.49e/Å 3 , Min. = −0.18 e/Å 3
Fig. 10 Conformation of peptide II (VF) with residue labelling