Dissertation/Thesis Abstract

Substitution and Oxidation Reactions of Cyclodiphosph(III)Azane Compounds of the Group 15 Elements
by Musongong, Joseph T., Ph.D., The University of North Dakota, 2020, 247; 27964374
Abstract (Summary)

In the first part of this work, the substitution of the chloride ligand on group 15 element bis(tert-butylamido)cyclodiphosph(III)azane monochlorides, {[(tBuNP)2(tBuN)2]ECl}, where E = P, As, Sb and Bi, with various monodentate ligands is rerported. The reaction of one equivalent of PhMgCl with {[(tBuNP)2(tBuN)2]ECl}, resulted in the isolation of {[(tBuNP)2(tBuN)2]EPh} 2b (E = As) or 4b (E = Bi), while the reaction of LiN(SiMe3)2 with {[(tBuNP)2(tBuN)2]ECl} gave {[(tBuNP)2(tBuN)2]EN(SiMe3)2} 2d (E = As) or 4d (E = Bi) in good yields. Compounds {[(tBuNP)2(tBuN)2]AsL} 2c (L = N3 ), 2e (L = OtBu) and 2f (L = OPh) were isolated by treating {[(tBuNP)2(tBuN)2]AsCl} with one equivalent of NaN3, NaOtBu and LiOPh, respectively. The non coordinating salt, {[(tBuNP)2(tBuN)2]SbOSO2CF3} 3g, was isolated by treating AgOSO2CF3 with {[(tBuNP)2(tBuN)2]SbCl} in THF. Similarly, compounds {[(tBuNP)2(tBuN)2]EI} 1h (E = P), 2h (E = As) and 3h (E = Sb) were isolated by treating {[(tBuNP)2(tBuN)2]ECl} with one equivalent of NaI in THF. The structures of 2b, 2c, 4d, 3g, 1h, 2h and 3h were determined by multi-nuclear NMR spectroscopy and elemental analyses and confirmed by X-ray crystallography.

In the next part of this work, the oxidation of the group 15 element bis(tert-butylamido)cyclodiphosph(III)azane compounds to cyclodiphosph(III/V)azane compounds, without elimination, using sulfur and selenium as the oxidizing agent is reported. First, treating {[(tBuNP)2(tBuN)2]EL} with one equivalent of sulfur or selenium furnished the monosulfides or -selenides {[(tBuNP)2(tBuN)2A]EL} 1aSe (E = P, A = Se, L = Cl), 2aS (E = As, A = S, L = Cl), 2aSe (E = As, A = Se, L = Cl) and 2bS (E = As, A = Se, L = Ph). The treatment of {[(tBuNP)2(tBuN)2]PPh} with one equivalent of selenium gave {[(tBuNP)2(tBuN)2](P=Se)Ph} 1bSe′ in which only the P(III) atom above the P2N2 ring is oxidized. Secondly, treating {[(tBuNP)2(tBuN)2]EL} with two equivalents of sulfur or selenium furnished the disulfides or -selenides, {[(tBuNP=A)2(tBuN)2]EL} 1aSe2 (E = P, A = Se, L = Cl), 2aS2 (E = As, A = S, L = Cl), 2aSe2 (E =As, A = Se, L = Cl), 2bS2 (E = As, A = S, L = Ph), 2bSe2 (E = As, A = Se, L = Ph), 2cSe2 (E = As, A = Se, L = N3), 3aS2 (E = Sb, A = S, L = Cl), 3bS2 (E = Sb, A = S, L = Ph), 3bSe2 (E = Sb, A = Se, L = Ph), 3cS2 (E = Sb, A = S, L = N3) and 3cSe2 (E = Sb, A = Se, L = N3). These compounds were characterized by X-ray crystallography, multi-nuclear NMR spectroscopy and elemental analyses.

The third part of this dissertation covers the oxidation of {[(tBuNP)2(tBuN)2]PL} (L = Cl or Ph) with selenium, in which the post-oxidation product shows the elimination of a molecule, tBuCl or isobutene. When {[(tBuNP)2(tBuN)2]PCl} and excess selenium were refluxed in toluene {[(tBuNP=Se)2(NH)2(NtBu(H)P=Se)]} 1aSe2Se′ was obtained with the elimination of tBuCl and the attachment of NHtBu group to the P(V) atom above the P2N2 ring and all the P(III) atoms being oxidized to P(V) atoms. On the other hand, when {[(tBuNP)2(tBuN)2]PPh} and excess selenium were heated at high temperatures, {[(tBuNP=Se)2(NH)2](P=Se)Ph} 1bSe2Se′ was isolated in which the tert-butyl groups on the amino nitrogen atoms are eliminated. The structures of 1aSe2Se′ and 1bSe2Se′ were determined by multi-nuclear NMR spectroscopy and elemental analyses and confirmed by single crystal X-ray analyses.

The final part of this work describes the syntheses and characterization of compounds derived from the reaction of cis-[(tBuNP)2(RNLi.thf)2] (R = Cy or tBu) with AsCl3, SbCl3 and PhPCl2. The reaction of cis-[(tBuNP)2(RNLi.thf)2] with the above electrophiles gave compounds {[(tBuNP)2(CyN)2]ECl} 2aCy (E = As), 3aCy (E = Sb) and {[(tBuNP)2(tBuNP)2]Ph2Cl2} 1ab. When 1ab was refluxed with magnesium powder, compound [(tBuNP)2(tBuN)2]P2Ph2 1bb was obtained. These compounds were characterized by X-ray, multi-nuclear NMR spectroscopy and elemental analyses.

Indexing (document details)
Advisor: Stahl, Lothar
Commitee: Hoffmann, Mark, Abrahamson, Harmon, Du, Guodong, Kolodka, Edward
School: The University of North Dakota
Department: Chemistry
School Location: United States -- North Dakota
Source: DAI-B 81/12(E), Dissertation Abstracts International
Source Type: DISSERTATION
Subjects: Inorganic chemistry, Chemistry
Keywords: Cyclodiphosph(III)azane, Diselenides, Ionic bond, Oxidation, Polar covalent, Substitution
Publication Number: 27964374
ISBN: 9798641721583
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