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The crystal structure of hexamethylcyclotriphosphazene  iodine (1:1 adduct) and the structural redetermination of sodium formate Markila, Peter Lennart
Abstract
This thesis consists of the structures of two compounds as determined by single crystal xray diffraction. The first structure is that of a phosphazene  iodine complex: hexamethylcyclotriphosphazene  iodine (1:1 adduct) and the second structure is the redetermination of sodium formate. Crystals of hexamethylcyclotriphosphazene  iodine (1:1 adduct) are triclinic, a = 10.707(13), b = 8.873 (5), c = 8.871(6)Å, α = 96. 65 (6), β = 103.91 (12), ɤ = 97.81(12)°, Z = 2, spacegroup PI. The structure was determined with MoK« diffractometer data by Patterson and Fourier synthesis, and was refined by fullmatrix leastsquares calculations to R = 0.053 for 1934 observed reflexions. The iodine molecule is weakly bonded to a nitrogen atom on the phosphazene ring, N  I = 2.417(7), I  I = 2. 823 (1) Å, N  I  I = 177.8(2)°. The sixmembered phosphazene ring is slightly, but significantly, ncnplanar, the conformation being that of a chair. The molecule has pseudom symmetry. Two distinct PN bonds are present; the longer ones, mean P  N = 1.64 Å, involve the nitrogen that is weakly bonded to the iodine molecule, while the other four PN bonds are equivalent, mean P  N = 1.598 Å. All the P  C bonds are equivalent, mean P  C = 1.789 Å. The mean endocyclic N  P  N and P  N  P angles are 114.7 and 124.0° respectively, while the mean exocyclic C  P  C angle is 104°. Crystals of sodium formate are mcnoclinic, a = 6.2590 (6), b = 6.7573 (16) , c = 6.716 (5) Å, β = 116.140(6)°, Z = 4, spacegrcup C2/c. The structure was determined by direct methods, and was refined by electron density and fullmatrix leastsquares procedures to E = 0.022 for 250 reflexions. Sodium formate is planar and has C2V symmetry. Partial charges were refined on the formate ion. The partial charges found on each atom are as follows: 0 0.23(1)e, C +0.16(3)e, H 0.49(10)e, and Sa +0.79(14)e. The sodium ion has six oxygen neighbours at an average distance of 2.45 Å and there are weak Na. ..0 interactions. There is a C  H...Na hydrogen bond which forms continuous rows of sodium formate ions. The C  0 bond distance is 1.246(1)Å and the 0  C  0 angle is 126.3(2)°.
Item Metadata
Title 
The crystal structure of hexamethylcyclotriphosphazene  iodine (1:1 adduct) and the structural redetermination of sodium formate

Creator  
Publisher 
University of British Columbia

Date Issued 
1974

Description 
This thesis consists of the structures of two compounds as determined by single crystal xray diffraction. The first structure is that of a phosphazene  iodine complex: hexamethylcyclotriphosphazene  iodine (1:1 adduct) and the second structure is the redetermination of sodium formate.
Crystals of hexamethylcyclotriphosphazene 
iodine (1:1 adduct) are triclinic, a = 10.707(13),
b = 8.873 (5), c = 8.871(6)Å, α = 96. 65 (6), β = 103.91 (12), ɤ = 97.81(12)°, Z = 2, spacegroup PI. The structure was determined with MoK« diffractometer data by Patterson and Fourier synthesis, and was refined by fullmatrix leastsquares calculations to R = 0.053 for 1934 observed reflexions. The iodine molecule is weakly bonded to a nitrogen atom on the phosphazene ring, N  I = 2.417(7), I  I = 2. 823 (1) Å, N  I  I = 177.8(2)°. The sixmembered phosphazene ring is slightly, but significantly, ncnplanar, the conformation being that of a chair. The molecule has pseudom symmetry. Two distinct PN bonds are present; the
longer ones, mean P  N = 1.64 Å, involve the nitrogen that is weakly bonded to the iodine molecule, while the other four
PN bonds are equivalent, mean P  N = 1.598 Å. All the
P  C bonds are equivalent, mean P  C = 1.789 Å. The mean endocyclic N  P  N and P  N  P angles are 114.7 and 124.0° respectively, while the mean exocyclic C  P  C angle is 104°.
Crystals of sodium formate are mcnoclinic, a = 6.2590 (6), b = 6.7573 (16) , c = 6.716 (5) Å,
β = 116.140(6)°, Z = 4, spacegrcup C2/c. The structure was determined by direct methods, and was refined by electron density and fullmatrix leastsquares procedures to E = 0.022 for 250 reflexions. Sodium formate is planar and has C2V symmetry. Partial charges were refined on the formate ion. The partial charges found on each atom are as follows: 0 0.23(1)e, C +0.16(3)e, H 0.49(10)e, and Sa +0.79(14)e. The sodium ion has six oxygen neighbours at an average
distance of 2.45 Å and there are weak Na. ..0 interactions. There is a C  H...Na hydrogen bond which forms continuous rows of sodium formate ions. The C  0 bond distance is 1.246(1)Å and the 0  C  0 angle is 126.3(2)°.

Genre  
Type  
Language 
eng

Date Available 
20100121

Provider 
Vancouver : University of British Columbia Library

Rights 
For noncommercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

DOI 
10.14288/1.0061154

URI  
Degree  
Program  
Affiliation  
Degree Grantor 
University of British Columbia

Campus  
Scholarly Level 
Graduate

Aggregated Source Repository 
DSpace

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Item Citations and Data
Rights
For noncommercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.