| dc.contributor.author | Bakshi, Pradip Kumar. | en_US |
| dc.date.accessioned | 2014-10-21T12:37:10Z | |
| dc.date.available | 1995 | |
| dc.date.issued | 1995 | en_US |
| dc.identifier.other | AAINN08722 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55081 | |
| dc.description | This report deals with two aspects of x-ray crystallography, (i) structural electron density determination and (ii) classification and geometry of hydrogen bonding to aromatic $\pi$ systems. | en_US |
| dc.description | (i) Structural and electron density determination. The compound, 3- ((p-nitrophenoxy)methyl) -3-chlorodiazirine, C$\rm\sb8H\sb6N\sb3O\sb3$Cl, was chosen because of its stability in x-ray radiation. The nature of bonding in diazirine ring is also a long standing question. The compound is triclinic, P1, with a = 6.034(1) A, b = 8.429(3) A, c = 9.805(2) A, $\alpha$ = 107.51(2)$\sp\circ$, $\beta$ = 96.58(2)$\sp\circ,$ $\gamma$ = 91.21(1)$\sp\circ,$ V = 471(1) A$\sp3,$ Z = 2. The diazirine ring skeleton is normal with N = N distance of 1.222(5) A and N-C-N angle of 49.8(3)$\sp\circ.$ The deformation density studies show that the diazirine ring in this compound possesses some degree of $\pi$-complex character. | en_US |
| dc.description | Aziridinocyclotriphosphazene compounds are of interest because of their effectiveness as anticancer drugs. Monochloropentaaziridinocyclotriphosphazene, N$\rm\sb3P\sb3(az)\sb5Cl$ is one of the promising examples. The compound N$\rm\sb3P\sb3(az)\sb5Cl$ is triclinic, P1, a = 8.665(1) A, b = 14.013(2) A, c = 7.965(1) A, $\alpha$ = 90.49(1)$\sp\circ,$ $\beta$ = 113.62(1)$\sp\circ,$ $\gamma$ = 89.92(1)$\sp\circ,$ V = 886.1(2) A$\sp3,$ Z = 2. The phosphazene ring is slightly puckered. The P-N bond lengths related to P which has Cl bonded to it, are shorter than the others. Both bow tie I and bow tie II conformational az rings are present in this compound. The electron density studies show that the nature of bonding in the tricy-clophosphazene ring is consistent with the Dewar Island model. | en_US |
| dc.description | (ii) Classification and geometry of hydrogen bonding to aromatic $\pi$ system. To understand the nature and significance of hydrogen bonds of the type X-H...$\pi$(aromatic) (X = N, O), crystal structures of nineteen tetraphenylborate (TB) salts of organoammonium cation and (Li(H$\rm\sb2O)\sb4\rbrack\sp+$ have been determined. These structures plus a few literature structures of TB salts provide a large variety of H(X)...$\pi$ bonds which has been classified as normal, bifurcated (interion, intracation, homodesmic and hetorodesmic) and trifurcated. The cation orientation in the TB compound where the H-bond is claimed with respect to that in non-hydrogen bonded compounds is opposite. This demonstrates that the H(X)...$\pi$ interaction in TB compounds is a positive tendency rather a passive response to overall packing requirements in the crystal. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1995. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Chemistry, Organic. | en_US |
| dc.subject | Chemistry, Physical. | en_US |
| dc.title | Charge density studies of 3-((p-nitrophenoxy)methyl)-3-chlorodiazirine and monochloropentaaziridinocyclotriphosphazene and hydrogen bonding in pi-arene systems. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
