Beiträge zur Phosphor-Stickstoff- und Schwefel-Stickstoff-Chemie

This thesis focuses on the experimental and theoretical
investigation of small molecules containing phosphorus, nitrogen
and sulfur. The first part of this work presents synthesis and
characterisation of molecules bearing a P-N-N-group:
N,N´,N´-[tris(trimethylsilyl)]-hydrazino-diphenylphosphane,
(TMS)2N-(TMS)N-PPh2, and
N,N´,N´-[tris(trimethylsilyl)]-hydrazino-phenyl(chloro)phosphane,
(TMS)2N-(TMS)N-P(Cl)Ph, were obtained in the reaction of
bis-[lithiumtris(trimethylsilyl)hydrazide] with PhnPCl3 - n (n = 1,
2). The structure and bonding of both species are discussed on the
basis of experimentally observed (X-ray, Raman, NMR, and MS) and
theoretically obtained data (B3LYP/6-31G(d,p), NBO analysis).
Oxidation with sulfur and selenium results in the formation of
(TMS)2N-(TMS)N-P(S)-Ph2, (TMS)2N-(TMS)N-P(Se)Ph2,
(TMS)2N-(TMS)N-P(S)Ph(Cl) and (TMS)2N-(TMS)N-P(Se)Ph(Cl). Moreover,
the thermal decomposition of
N,N´,N´-[tris(trimethylsilyl)]hydrazine-dichlorophosphane,
(TMS)2N-(TMS)N-PCl2 and the reaction with magnesium have been
investigated. The formation and molecular structure of the novel
MgCl2(THF)2* 2Mg[(TMS)NP(O)2N(TMS)2](THF) salt containing the
hitherto unknown (TMS)NP-(O)2N(TMS)22- anion are discussed. DFT
calculations (B3LYP/6-311+G(3df,2p)//B3LYP/6-31G(d,p)) are used to
evaluate the bonding, ground-state structures, and energy landscape
for the different isomers of (TMS)2N-(TMS)N-PCl2: the
thermodynamics and kinetics of the successive elimination of
chlorotrimethylsilane (TMS-Cl) resulting in the formation of
covalent azide analogues such as TMS-PNN or TMS-NNP are discussed.
While investigating the reaction of (TMS)2N-(TMS)N-PCl2 with Lewis
acides a galliumtrichloride-adduct of
4-bis[trimethylsilylamino]-1,2,4,3,5-triazadiphosphole was
discovered. This hitherto unknown triazadiphosphole represents one
of the few examples of a five-membered ring-molecule containing
only phosphorus and nitrogen. This ring system was unequivocally
characterized by X-Ray, Raman, NMR and MS analysis. Furthermore the
Staudinger-type reaction of
N,N´,N´-[tris(trimethylsilyl)]-hydrazino-diphenylphosphane with
SP(N3)3 and and C3N12 in different stoichiometries were
investigated. It is possible to substitute only one azide group in
SP(N3)3 and up to two azide groups in C3N12 with
(TMS)2N-(TMS)N-PPh2, resulting in the expected products. Upon
heating of a solution of (TMS)2N-(TMS)N-PPh2 and SP(N3)3 a new
eight-membered ring containing phosphorus and nitrogen in
alternating order was obtained. The molecule contains a long
pnicogene-chain (eleven atoms in total, three phosphorus- and eight
nitrogen-atoms). The reactions of (NSCl)3 and NSCl2- with AgX salts
(X = CN, SCN, OCN), as well as the reaction of (NSCl)3 with [PPh4]X
(X = CN, SCN, OCN) and HgX (X = CN, SCN) have been investigated in
a combined experimental and theoretical study. Additionally, the
reaction of NSCl2- salts with hydride-transferring-agents like
NaBH4 or NaBH3CN was studied. The thermodynamics as well as
structure and bonding of the formation of NSX, NSX2- and NSXY- (X,
Y = Cl, H, CN, SCN, OCN) have been studied. Unfortunately the
preparation of these species did not suceed. The substitution of
sulfur by selenium with SeO2, as reported by Rawson, was
investigated on the salts of NSCl2- and S2N3+. These reactions
resulted polymeric products and selenium; the formation of a
nitrogen-selenium-species could not be confirmed.