A Folded Conformation around the Methylene Group in Simple Boc–NH–(CH2)3–NH–Boc: An X-ray Diffraction Study

2002 ◽  
Vol 2002 (12) ◽  
pp. 640-641 ◽  
Author(s):  
Pooja Anjali Mazumdar ◽  
Amit Kumar Das ◽  
Valerio Bertolasi ◽  
Sandip Kumar Kundu ◽  
Animesh Pramanik
Keyword(s):  
Nucleic Acid ◽  
Diffraction Study ◽  
Peptide Nucleic Acid ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Model Compounds ◽  
X Ray ◽  
Methylene Group ◽  
Inherent Tendency

Structural studies on model compounds Boc–NH–(CH2)2–NH–Boc (1) and Boc–NH–(CH2)3–NH–Boc (2) have shown the inherent tendency of the propylene group to adopt a folded conformation, which may help in peptide and peptide nucleic acid (PNA) design.

Structural studies in the ruthenium(II)/(±)-ortho-Phenylenebis{methyl(phenyl)-phosphine/arsine} system. I. Crystal structure of trans-Carbonylhydridobis-[(±)-ortho-phenylenebis {methyl(phenyl)phosphine)]ruthenium(II)hexafluorophosphate(V)-acetone (1/2)

1983 ◽  
Vol 36 (2) ◽  
pp. 259 ◽  
Author(s):  
SC Grocott ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Diffraction Study ◽  
Crystal And Molecular Structure ◽  
Title Complex ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ruthenium Atom ◽  
Methyl Phenyl

The crystal and molecular structure of the title complex, trans-[RuH(CO)(opmpp)2]+ (PF6)-.2(CH3)2- CO [opmpp ≡ (�)-ortho-phenylenebis {methyl(phenyl)phosphine) , o-C6H4(PMePh)2], has been established by a single-crystal X-ray diffraction study at 295(1) K, being refined to a residual of 0.066 for 2293 independent 'observed' reflections. Crystals are monoclinic, C2/c, a 11.943(4), b 26.151(9), c 15.974(6) �, β 90.97(7)�, Z 4. In the model adopted, the ruthenium atom is located on a crystallographic twofold axis; the carbonyl and hydrido ligands lie trans to each other and are disordered about the ruthenium atom. The ruthenium-phosphorus distances are 2.320(2) and 2.317(2)�.

Structural studies in the ruthenium(II)/(±)-ortho-Phenylenebis{methyl(phenyl)-phosphine/arsine} system. III. Crystal structures of Dichlorocarbonyl(dimethyl sulfoxide)-[ortho-phenylenebis {methyl(phenyl)phosphine}]ruthenium(II) and of cis-dicarbonyldichloro[(±)-ortho-phenylenebis{methyl(phenyl)arsine}]ruthenium(II)

1983 ◽  
Vol 36 (2) ◽  
pp. 271 ◽  
Author(s):  
SR Hall ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Diffraction Study ◽  
Dimethyl Sulfoxide ◽  
Crystal And Molecular Structure ◽  
Title Complex ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbonyl Ligands ◽  
Methyl Phenyl

The crystal and molecular structure of the title complex, cis-[Ru(CO)Cl2(dmso)(opmpp)] (1) (dmso ≡ dimethyl sulfoxide, Me2SO; opmpp ≡ (�)-ortho-phenylenebis {methyl(phenyl)phosphine},[o-C6H4(PMePh)2]), has been determined by a single-crystal X-ray diffraction study at 295(1) K, being refined to a residual of 0.050 for 6115 independent 'observed' reflections. Crystals are monoclinic, P21/c, a 11.180(7), b 12.957(6), c 17.567(9) �, β 90.88(5)�, Z 4. The ruthenium-chlorine distances, trans to phosphine and carbonyl ligands, respectively, are 2.469(2), 2.446(2) �; the ruthenium-phosphine distances, trans to the chloride and dimethyl sulfoxide ligands, respectively, are 2.292(1), 2.313(2) �. Ruthenium-sulfur (dmso) is 2.380(2) �, while the ruthenium-carbon(CO) is c. 1.72 �. For cis-[Ru(CO)2Cl2(opmpa)] (2) (opmpa ≡ (�)-ortho-phenylenebis{methyl(phenyl)- arsine}, [o-C6H4(AsMePh)2]), refinement led to a residual of 0.036 for 2423 independent 'observed' reflections. Crystals are monoclinic, P21/c, a 10.497(3), b 11.586(7), c 20.341(9) �, β 105.31(4)�, Z 4. Ruthenium-arsine distances, trans to carbonyl and chlorine ligands, respectively, are 2.404(1), 2.455(1) �. Ruthenium-chlorine distances, trans to arsine and carbonyl ligands, respectively, are 2.443(3), 2.433(2) �, while ruthenium-carbon(CO) distances, trans to arsine and chlorine ligands, respectively, are 1 .920(8), 1 .872(8) �.

Structural studies in the ruthenium(II)/(±)-ortho-Phenylenebis{methyl(phenyl)-phosphine/arsine) system. II. Crystal structure of trans-Dichloro[(±)-ortho-phenylenebis{methyl(phenyl)-phosphine}][(±)-ortho-phenylenebis(methyl(pheny1)-phosphine) P-oxide]ruthenium(II)

1983 ◽  
Vol 36 (2) ◽  
pp. 267 ◽  
Author(s):  
SR Hall ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Diffraction Study ◽  
Crystal And Molecular Structure ◽  
Title Complex ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Distance ◽  
Methyl Phenyl

The crystal and molecular structure of the title complex, trans-[RuCl2{(�)-o-C5H4(PMePh)2}{(�)- o-C5H4(PMePh)(P(O)MePh)}], has been established by a single-crystal X-ray diffraction study at 295(1) K, being refined to a residual of 0.037 for 2669 independent 'observed' reflections. Crystals are orthorhombic, P212121, a 16.655(5), b 15.805(4), c 14.823(8) �, Z 4. The chlorine atoms lie trans to each other in the coordination sphere of the six-coordinate ruthenium, with the O-C6H4(PMePh)2 and o-C6H4(PMePh)(P(O)MePh) ligands being P,P? and O,P' bidentate respectively. The ruthenium-chlorine distances are 2.434(2) and 2.425(2) �; the two mutually trans ruthenium- phosphine distances are 2.310(3) and 2.346(2) �, but that which is trans to the oxygen is unusually short, being 2 219(2) �. The ruthenium-oxygen distance is 2.166(5)�.

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