Sterically Tuned P-Phosphanylamino Phosphaalkenes (Me3Si)2C=PN(R)PPh2 and (iPrMe2Si)2C=PN(R)PPh2

Article abstract of DOI:10.1002/zaac.201700446

Deprotonation of the aminophosphanes Ph₂PN(H)R 1a–1h [R = tBu (1a), 1-adamantyl (1b), iPr (1c), CPh₃ (1d), Ph (1e), 2,4,6-Me₃C₆H₂ (Mes) (1f), 2,4,6-tBu₃C₆H₂ (Mes*) (1g

Full text of DOI:10.1002/zaac.201700446

Journal of Inorganic and General Chemistry
DOI: 10.1002/zaac.201700446
ARTICLE
Zeitschrift für anorganische und allgemeine Chemie
Sterically Tuned P-Phosphanylamino Phosphaalkenes
(Me3Si)2C=PN(R)PPh2 and (iPrMe2Si)2C=PN(R)PPh2
Roxana M. Bîrzoi,[a] Daniela Lungu,[a] Peter G. Jones,[a] Rainer Bartsch,[a] and Wolf-W. du Mont*[a]
Abstract. Deprotonation of the aminophosphanes Ph2PN(H)R 1a–1h
[R = tBu (1a), 1-adamantyl (1b), iPr (1c), CPh3 (1d), Ph (1e), 2,4,6- 2b, 3a, and 3b, with bulky N-alkyl groups the Si2C=P–N–P skeleton
Me3C6H2 (Mes) (1f), 2,4,6-tBu3C6H2 (Mes*) (1g), 2,6-iPr2C6H3 is non-planar (orthogonal conformation), whereas 3g, 3h, and 4g with
ported by X-ray structure determinations, reveal that in compounds 2a,
(DIPP) (1h)], followed by reactions of the phosphanylamide salts bulky N-aryl groups exhibit planar conformations of the Si2C=P–N–P
Li[Ph2PNR] 2a, 2b, 2g, and 2h with the P-chlorophosphaalkene skeleton. Solid 3g and 4g exhibit cisoid orientation of the planar C=P–
(Me3Si)2C=PCl, and of 2a–2g with (iPrMe2Si)2C=PCl, gave the iso-
N–C units (planar I) but in solid 3h the transoid rotamer is present
lable P-phosphanylamino phosphaalkenes (Me3Si)2C=PN(R)PPh2 3a, (planar II). From 3g, 4d, and 4g mixtures of rotamers were detected
3b, 3g, and (iPrMe2Si)2C=PN(R)PPh2 4a–4g. 31P NMR spectra, sup-
in solution by pairs of 31P NMR patterns (3h: line broadening).
Towards chlorodiphenylphosphane, however, the 1-aza-2-
phosphaallyl anions of Li[(Me3Si)2C=PNR] (R = tBu,[2,6,7]
Mes* [6]) acted as P-nucleophiles leading, according to 31P
NMR spectroscopic data, preferentially to the type D P-di-
phenylphosphanylphosphorane isomers [(Me3Si)2C=](RN=)P–
PPh2.[3,6–8] From Li[(Me3Si)2C=PNtBu with chlorodiisoprop-
ylphosphane, the corresponding type D product was obtained,
accompanied by the isomeric P-phosphanylazaphosphirane
structure (type E) according to 31P NMR spectroscopy.
With chloro(isopropyl)t-butylphosphane as substrate for
Li[(Me3Si)2C=PNtBu, the reaction was selective leading to the
single crystalline product (Me3Si)2C=PN(tBu)P(tBu)(iPr),
which was characterized by X-ray crystallography as a new
example of the type D structure (Scheme 2, center).[7] Only
one compound of the phosphanylphosphorane type D structure
had previously been investigated crystallographically; it was
synthesized by (Me3Si)2C transfer from a carbenoid precursor
to the bulky P-phosphanyliminophosphane tBu2PP=NMes*
(Scheme 2, bottom).[9] Since Li[(Me3Si)2C=PNtBu] acts selec-
tively as a P-nucleophlile towards diphenyl and dialkyl chloro-
phosphanes, we chose, as an alternative access to type A PNP
ligands, the inverse route using metallated aminophosphanes
and P-chlorophosphaalkenes (Scheme 3).[3] Fortunately,
metallated aminophosphanes such as Li[Ph2PN(1-Ada)][3] act
towards the P-chlorophosphaalkene (Me3Si)2C=PCl selec-
tively as N-nucleophiles, delivering the desired type A ligands.
In the following we presemt some novel synthetic results con-
cerning this reaction route. These syntheses provide mono-un-
saturated bidentate diphenylphosphanylamino-phosphaalkene
ligands (type A) of varied steric encumbrance.[8]
Introduction
We have recently studied the “hybrid” P-phosphanylamino
phosphaalkene ligands (Me3Si)2C=PN(R)PRЈ2 (Scheme 1, A)
with the intention of combining the features of classic small
bite angle iminobisphosphane “PNP” ligands RN(PRЈ2)2 (B)[1]
with those of thermally more labile amino-bridged bis-phos-
phaalkenes (C).[2]
The enhanced electrophilicity of the phosphaalkene phos-
phorusatomofthecoordinatedtypeAchelateligand(Me3Si)2C=
PN(1-Ada)PPh2 led to exceptional ClǞP coordination (chlo-
rotropy); reactions with PtCl2 and PdCl2 led to uncharged com-
plexes M[(Me3Si)2C=P(Cl)N(1-Ada)PPh2]2 (M = Pd, Pt) that
involved anionic chelate ligands [(Me3Si)2C=P(Cl)N(1-Ada)
PPh2]– with P–Cl bonds.[3] Subsequently, reactions of type A
ligands with RhI chlorido complexes were shown to involve
RhCO-assisted P–C coupling reactions with loss of (Me3Si)2C=
C=O, leading from the type A compounds to dianionic tetra-
dentate ligand units in the coordination sphere of an RhIIICl
unit.[4]
To obtain synthetic access to type A ligands, we initially
attempted to use metallated P-aminophosphaalkenes (1-aza-2-
phosphaallyl anions)[5,6,7] for P–N coupling reactions with
chlorodiphenylphosphane, analogous to P–N coupling reac-
tions of metallated P-aminophosphaalkenes with P-chloropho-
sphaalkenes,[2,8] which are known to deliver the “doubly unsat-
urated” type C ligands (Scheme 2, top).
* Prof. Dr. W.-W. du Mont
Fax: +49-531-3915387
E-Mail: w.du-mont@tu-bs.de
[a] Institut für Anorganische und Analytische Chemie
Technische Universität Braunschweig
Hagenring 30
Results and Discussion
Aminophosphanes
38106 Braunschweig, Germany
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/zaac.201700446 or from the au-
thor.
Various aminophosphanes Ph2PN(H)R[10] 1a–1h [R = tBu
(1a), 1-adamantyl (1b), iPr (1c), CPh3 (1d), Ph (1e), 2,4,6-
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Scheme 1. Various types of iminoorganophosphorus species with P–N–P or P–P–N backbones.
Scheme 2. Access to PNP and PPN species via (top and center)[2,7] N–P and P–P coupling reactions of 1-aza-2-phosphaallyl anions; (below)
the reaction leading to the first low-coordinated phosphanyl(alkylidene)(imino)phosphorane.[9]
Me3C6H2 (Mes) (1f), 2,4,6-tBu3C6H2 (Mes*) (1g), 2,6-
iPr2C6H3 (DIPP) (1h)], including a few examples with particu-
larly bulky substituents, were chosen as starting materials for
metallation reactions. The solid-state structures of 1b, 1f, and
of oxidized 1f(P=O) were determined by X-ray crystallography
(see Scheme 3, Experimental Section, Table 3, and Figures S1–
S3, Supporting Information).
Synthesis of Phosphanylamino Phosphalkenes
Aminophosphanes were deprotonated at –40 °C with lithi-
umdiisopropyl amide (LDA) in mixtures of solvents containing
THF; only for 1d nBuLi was used. Solutions of the lithium
derivatives 2a–2h were added dropwise to the P-chlorophos-
phaalkenes (Me3Si)2C=PCl and / or (iPrMe2Si)2C=PCl at
–40 °C leading with (partial) precipitation of LiCl to the P-
diphenylphosphanylamino phosphaalkenes 3 or 4 (Scheme 3),
which are soluble in hydrocarbons.
All products were identified by 31P NMR, but only 3a, 3b,
3g, 4b, and 4e were isolated in bulk as yellow solids. From all
four products 3 (3a, 3b, 3g, and 3h) single crystals were ob-
tained, even though the bulk of 3h was an impure solid. Simi-
larly a single crystal of 4g was picked from an impure solid
Scheme 3. The route to P-phosphanylamino phosphaalkenes 3 and 4.
sample. P-Diphenylphosphanylamino phosphaalkenes 3 and 4
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are air- and moisture-sensitive compounds; pure samples can upfield shift of the 31P(=C) nucleus, whereas the 31P(Ph2) nu-
be stored under inert gas for an extended time. cleus is scarcely affected (Table 1).
NMR Spectroscopic Characterization
31P NMR spectroscopic data of compounds 3 and 4 are col-
lected in Table 1. 31P- and 13C-spectroscopic investigations on
related P-aminophosphaalkenes (Me3Si)2C=PN(R)RЈ (R =
alkyl, RЈ = H, alkyl, or trimethylsilyl) have revealed that favor-
able n(N)Ǟπ(P=C) conjugation in 3-center, 4-electron π-bond
systems correlates with significant upfield shifts in relation to
isolated P=C bonds.[5] P-Amino groups with two very bulky
subsituents such as tert-butyl, trimethylsilyl, or 2,2,6,6-tet-
ramethylpiperidyl, however, tend for steric reasons to confor-
mations exhibiting orthogonal orientation of the amino groups
with respect to the phosphaalkene plane Si2C=P.[5,11] When
Scheme 4. Idealised coplanar and orthogonal conformations of phos-
phanylamino phosphaalkenes, Si (black circles) = Me3Si or iPrMe2Si,
R (red Circles) = alkyl or aryl. Left: planar I, center: planar II, right:
orthogonal.
In the cases of the bulky aromatic substituents and of the
one of the bulky substituents is an aryl group, such as 2,4,6- trityl group, two species are present in solution, as indicated
tBu3C6H2– (Mes*), the aromatic ring plane of the latter can by two sets of AM patterns in the 31P NMR spectra of 3g, 4g
rotate into a position orthogonal to the nitrogen plane, allowing (R = Mes*) and of 4d (R = CPh3), and by line broadening in
the latter to adopt a conformation with nearly coplanar phos- the spectra of 3h and 4f. The resonances of the 31P(=C) nuclei
phaalkene and nitrogen planes; in the related compound from the two AM patterns of each of the compounds 3g and
(Me3Si)2C=PN(Mes*)SiMe3 the dihedral angle between the 4g differ by only 7 ppm, whereas the resonances of the
amino group and the nodal plane Si2C=P of the double bond 31P(Ph2) nuclei differ by about 20 ppm. The varying magni-
is 11.2°.[11]
tudes of the NMR couplings 2J(P,P) in the range from 6.6 (4a)
In our choice of P-diphenylphosphanylamino phosphaalk- to 67.5 Hz (4e) allow to suggest different relative orientations
enes, the 1-adamantyl, tert-butyl and trityl groups are very of the phosphorus lone pairs in the P–N–P moieties.[10a] The
2
bulky alkyls, and the PPh2 groups are sterically comparable to difference between the coupling constants J(P,P) of the two
SiMe3 or SiMe2Ph. All aminophosphaalkenes (Me3Si)2C= species of 3g is 14 Hz, but only 4 Hz in the case of 4g. These
PN(H)R and (iPrMe2Si)2C=PN(H)R that are related to 3a, 3b, differences reflect not only the different conformations of the
or 4a–4g exhibit 31P-NMR shifts between δ = 310 and C=P–N–P moieties (planar I or II, see Scheme 4), but also
326 ppm and 13C NMR shifts between 70 and 77 ppm,[8] possible differences in the rotational preferences of the N–
whereas among the phosphanylamino phosphaalkenes 3 and 4, PPh2 groups (rotation around this P–N bond, see Supporting
the 31P(=C) nuclei of the 1-adamantyl and tert-butyl deriva- Information, Figure S1).[10a]
tives 4a, 4b exhibit significantly deshielded resonances in 31P
Oxidation of the PPh2 phosphorus atom of 3b [δ31P = 373.5
2
1
and 13C NMR, indicating a loss of n(N)Ǟπ(P=C) conjugation and 37.7 ppm, J(P,P) = 12.0 Hz, δ13C(=P) 190.5, J(P=C) =
(Scheme 4 and Experimental Section).[5,11] The exchange of R 98.8 Hz] with selenium leads to the compound (Me3Si)2C=
= tBu in 4a for R = iPr in 4c leads in the 31P NMR to a 40 ppm PN(1-Ada)P(=Se)Ph2 [3b(P=Se), δ31P = 350.4 and 45.7 ppm,
Table 1. 31P NMR spectroscopic data of P-phosphanylamino phosphaalkenes.
δ = 31P(=C) /ppm
δ = 31PPh2 /ppm
|2J(P,P)| /Hz
(Me3Si)2C=PN(R)PPh2
3a (R = tBu)
372.9
374.0
350.4
330.5
44.4
37.7
45.7 (P=Se)
74.0
11.5
12.1
3b (R = 1-adamantyl)[3]
3b(P=Se) (R = 1-adamantyl)
3g (R = Mes*)
7.1
337.7
55.1
21.0
3h (R = DIPP)
335.8 (broad), 58.8 (broad)
349.3
not resolved
59.4
3j (R = CH2Ph)[4,12]
39.4
(iPrMe2Si)2C=PN(R)PPh2
4a (R = tBu)
4b (R = 1-adamantyl)
4c (R = iPr)
382.3
385.7
342.7
366.5
47.0
38.3
43.6 (broad)
25.6
6.6
10.0
13.8
32.8
4d (R = CPh3)
361.5
15.4
40.0
4e (R = Ph)
4f (R = Mes)
4g (R = Mes*)
351.3
331.4 (broad)
341.2
60.9
63.8 (broad)
72.6
67.5
not resolved
30.5
337.7
50.2
26.2
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1
δ13C(=P) = 183.4 ppm, J(P,C) = 101.8 Hz], which does not slightly distorted planar II conformation with a transoid orien-
2
exhibit a resolvable coupling J(P,P).
tation of the P=C- and DIPP*-Cipso carbon atoms at the P–N
bond [torsion angle C1P1NP2 16.25(11)°]. In this structure,
the angle P1–N–Cipso is particularly narrow, compared with
the other compounds [110.8° (3h) versus 116.5° (3b) to
Structure Determinations
The molecular structures of compounds 3a, 3b, 3g, 3h, 4b, 128.38° (4g)], whereas the angles P1–N–P2 (125.8°) and P2–
and 4g are presented in Figure 1, Figure 2, Figure 3, Figure 4, N–Cipso (123.4°) are unusually wide (for selected distances
Figure 5, and Figure 6. The structures can be assigned on the and angles, see Table 2).
basis of the relative orientations of the PNCP and Si2C=PN
The large angles P1–N–Cipso of solid 3g and 4g may reflect
planes to the idealized cases of planar I or II or orthogonal the repulsions between bulky aryl groups and the neighboring
(Scheme 4). According to structure determinations the top- pair of trialkylsilyl groups.[11]
ologies of the backbones of the compounds with NMes*
The structures of the compounds with N-tBu and with N-
groups (3g, 4g) (the crystallized rotamers) are related to that 1-Ada groups (3a, 3b, and 4b) exhibit distorted orthogonal
of Chernegas’ compound (Me3Si)2C=PN(Mes*)SiMe3,[11] cor- conformations. The conformational differences planar vs. or-
responding to the planar I conformation with cisoid orientation thogonal are reflected in the interplay of the P–N distances of
of the P=C- and Mes*-Cipso carbon atoms at the P–N bond C=PN and NPPh2 groups in phosphanylamino phosphaalkenes,
[torsion angles C1P1NP2 179.44(7)° (3g) and 179.55° (4g)]. whereas the P=C distances are very similar at about 1.66 Å. In
Compound 3h, with an N-DIPP group, however, exhibits a
Figure 1. Structure of compound 3a in the crystal. Ellipsoids represent
50% probability levels.
Figure 3. Structure of compound 3g in the crystal. Ellipsoids represent
50% probability levels.
Figure 2. Structure of compound 3b in the crystal. Ellipsoids represent Figure 4. Structure of compound 3h in the crystal. Ellipsoids represent
50% probability levels.
30% probability levels.
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Scheme 5. Atom designation for the NMR assignment (bold letters)
1
proposed for the H and 13C nuclei of 4a and related compounds.
Figure 5. Structure of compound 4b in the crystal. Ellipsoids represent
50% probability levels.
structures assigned to the planar I and II types, P–N distances
of the C=PN moieties are shorter (1.70–1.71 Å) and the P–N
bonds involving the PPh2 groups are lengthened to 1.74 Å
(3h), 1.76 Å (4g), and 1.77 Å (3g). These effects, together with
the 31P-NMR shifts of the latter (downfield from those of 3a,
3b and 4a, 4b) correlate with some degree of N–P=C conjuga-
tion. N-aryl conjugation does not play a role, since the aro-
matic planes of the bulky N-aryl groups in 3g, 3h, and 4g are
not coplanar with the planar C1–P1–N–P2 backbones of these
phosphanylamino phosphaalkenes.
Conclusions
P-Phosphanylamino phosphaalkene ligands (RЈMe2Si)2C=
PN(R)PPh2 [R = Me (3), iPr (4)] are available from reactions
of lithium diphenylphosphanylamides Li[Ph2PNR] 2a–2h
[R = tBu (1a), 1-adamantyl (1b), iPr (1c), CPh3 (1d), Ph (1e),
2,4,6-Me3C6H2 (Mes) (1f), 2,4,6-tBu3C6H2 (Mes*) (1g),
2,6-iPr2C6H3 (DIPP) (1h)] with P-chlorophosphaalkenes
(RЈMe2Si)2C=PCl (RЈ = Me, iPr). Crystal structure determi-
nations of the monounsaturated bidentate PNP ligands 3a, 3b,
3g, 3h, 4b, and 4g allow classification of the structures, ac-
cording to the relative orientations of the PNCP and Si2C=PN
planes, to the idealized cases of planar (coplanar phosphaalk-
Figure 6. Structure of compound 4g in the crystal. Ellipsoids represent
50% probability levels. Only one position of the disordered SiMe2iPr
group is shown.
the structures 3a, 3b, and 4b with large torsion angles C1–P1– ene and nitrogen planes: 3g, 3h, 4g) and orthogonal (phos-
N–P2 (105–111°) and slightly pyramidalized nitrogen atoms phaalkene and nitrogen planes with large torsion angles: 3a,
(angle sums of 352°), the distances between the nitrogen and 3b, 4b). 3g and 4g (R = Mes*) exhibit cisoid orientation of the
the phosphaalkene phosphorus atoms (about 1.74 Å, single P=C- and Mes*-Cipso carbon atoms at the P–N bond (planar
bond) are slightly longer than those of the P–N single bonds I), whereas 3h (R = DIPP) crystallized with transoid orienta-
involving the PPh2 groups (about 1.72 Å). However, in the tion of the P=C- and DIPP*-Cipso carbon atoms at the P–N
Table 2. Selected distances /Å and angles /° within the backbones C1–P1–N(–C)–P2 of compounds 3 and 4.
d(P=C)
d(P1–N)
d(P2–N)
ϽC1–P1–N
ϽP1–N–C
ϽP2–N–C
ϽP1–N–P2
3a
3b
3h
3g
4a
4g
1.664(14)
1.665(2)
1.662(14)
1.663(11)
1.6609(12)
1.6609(11)
1.748(12)
1.748(12)
1.706(11)
1.712(9)
1.7393(10)
1.7077(9)
1.724(11)
1.721(11)
1.742(11)
1.771(9)
1.7227(10)
1.7603(9)
112.8(7)
111.5(5)
116.9(6)
120.9(5)
113.85(5)
121.55(5)
119.5(9)
116.5(7)
110.8(8)
126.1(7)
118.89(5)
128.38(7)
115.4(9)
118.37(7)
123.4(8)
116.6(7)
115.19(7)
113.24(7)
116.8(7)
119.3(5)
125.8(6)
117.2(5)
117.67(6)
118.38(5)
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triethylamine (4.5 mL, 31.0 mmol) and 2.52 g (11.43 mmol) 2,4,6-tri-
bond (planar II). The structures of the compounds with N-tBu
methylaniline gave after 12 h at room temperature 3.1 g (61%) yellow-
ish 1f, m.p. 87–89 °C. Single crystals suitable for X-ray diffraction
were grown from pentane. 1H NMR (200.1 MHz, C6D6):): δ = 7.5–
6.73 ppm (multiplets, aryl H), 3.61 [d, J(P,C) = 8.5 Hz, H–N], 2.2–2.1
(m, o-CH3), 1.93 (s, p-CH3). 13C NMR (50.32 MHz, C6D6): δ = 142.7
[d, J(P,C) = 15.7 Hz], 140.3 [d, J(P,C) = 14.2 Hz], 130.6 [d, J(C,P) =
3.6 Hz], 129.2 [d, J(P,C) = 17.4 Hz], 128.8 (s), 128.5(s), 128.2 [d,
J(P,C) = 6.3 Hz], 20.2 [d, J(P,C) = 3.9 Hz], 18.8 [d, J(P,C) = 6.0 Hz],
17.1(s). 31P NMR (81.02 MHz, C6D6):): δ = 36.6. From an NMR tube
and with N-1-Ada groups (3a, 3b, and 4b) exhibit distorted
orthogonal conformations, comparable to aminophosphaalk-
enes with N(SiMe3)2 groups.[5] The conformational differences
planar versus orthogonal are reflected in the interplay of the
P–N distances of C=PN and NPPh2 groups in phosphanylam-
ino phosphalkenes whereas the P=C distances are close to in-
variant at 1.66 Å. The lack of favorable π-overlap between the
nitrogen lone pairs and the P=C π orbitals in the orthogonal
conformations of 3a, 3b, and 4b with N-PPh2 and bulky N- a few single crystals of the oxide Ph2P(=O)N(H)(2,4,6-Me3C6H2)
[1f(P=O)] were isolated.
alkyl groups is also reflected in particularly low-field chemical
shifts of the 31P(=C) nuclei in the 31P NMR spectra of these
ligands.
Ph2PN(H)(2,6-iPr2C6H3) (1h): Chlorodiphenylphosphane (3 g,
13 mmol) in 60 mL pentane reacted with with 2,6-diisopropylaniline
(4.6 g, 26 mmol) for 2 d at room temperature. The white precipitate
was filtered off and the solvent evaporated at reduced pressure, to give
3.6 g (95%) 1h as a white solid. 1H NMR (200.1 MHz, C6D6): δ =
7.5–7.03 ppm (multiplets, aryl H), 3.82 [d, J(C,P) = 8.1 Hz], H-N), 3.0
(m, CH), 1.06 (s, CH3), 1.04 (s, CH3). 13C NMR (50.32 MHz, C6D6):
δ = 142.5 (s), 142.4 [d, J(C,P) = 19.1 Hz], 139.7 [d, J(C,P) = 12.6 Hz],
131.3 [d, J(C,P) = 20.6 Hz], 128.8 (s), 128.3 [d, J(C,P) = 6.3 Hz],
122.7 (s), 118.4 (s), 27.0 [d, J(C,P) = 14.7 Hz], 23.8 (s, CH3). 31P
NMR (81.02 MHz, C6D6): δ = 43.1 ppm.
Experimental Section
General Methods: All experiments were carried out in an oxygen-
free dry nitrogen atmosphere by using standard Schlenk techniques.
NMR spectra were recorded with Bruker spectrometers AC 200, Av-
ance 200, Avance 400, and AMX 300, with 85% H3PO4, and SiMe4
as external or internal standards.
Aminophosphanes: All aminophosphanes Ph2PNHR except the 1-ad-
amantyl, the trityl, the mesityl, and the 2,6-diisopropylphenyl (DIPP)
derivatives (1b, 1d, 1f, 1h) were prepared according to published
methods.[10]
Reactions of Metallated Aminophosphanes with (Me3Si)2C=PCl
and with (iPrMe2Si)2C=PCl; General Procedure: To the solution of
an alkyl- or arylaminodiphenylphosphane 1 in 10 mL of THF at –40 °C
was added dropwise an equimolar amount of LDA (2 m solution in
THF-heptane-ethylbenzene); subsequently the reaction mixture was al-
lowed to warm up to room temperature. A singlet signal in the 31P
NMR spectrum of the reaction mixture confirmed the presence of the
deprotonated species 2. After removal of the volatiles in vacuo the
residue was dissolved in THF and added dropwise at –40 °C to a solu-
tion of (Me3Si)2C=PCl or of (iPrMe2Si)2C=PCl in THF. After warming
up slowly to room temperature and further stirring for 1 h, all volatiles
were removed in vacuo and the residue was taken up in pentane. Re-
moval of LiCl by filtration through Celite® 535, followed by concen-
trating the pentane solution to dryness, furnished the products 3 [from
(Me3Si)2C=PCl] or 4 [from (iPrMe2Si)2C=PCl].
Ph2PN(H)1-Ada (1b):
A solution of adamantylamine (1.73 g,
11.43 mmol) in 35 mL pentane was treated with triethylamine (2.4 mL,
17 mmol) and chlorodiphenylphosphane (1.1 g, 5 mmol) at room tem-
perature. After 1 h, a white precipitate had separated from the solution.
Evaporation of all volatiles at reduced pressure provided 1a (5.34 g,
1
85%) as a white solid, m.p. 75–76 °C. H NMR (200.1 MHz, C6D6):
δ = 7.5–7.4 and 7.2–7.07 (multiplets, aryl H), 1,92 [d, J(P,H) =
3.7 Hz, Ada], 1.78 (s, br., Ada), 1.53 (s, br., Ada) ppm. 13C NMR
(50.32 MHz, C6D6): δ = 144.3 [d, 1J(P,C) = 13.3 Hz, ipso-C], 130.9
[d, 3J(C,P) = 20.4 Hz, m-C], 128.0 [s, p-C], 127.9 [d, 2J(C,P) = 6.2 Hz,
o-C], 50.9 [d, 2J(C,P) = 18.0 Hz, Ada], 45.8 [d, J(C,P) = 8.9 Hz, Ada],
36.2 (s, Ada), 29.9 [d, J(C,P) = 0.9, Ada] ppm. 31P NMR (81.02 MHz,
C6D6): δ = 18.9 ppm. C22H26NP (M = 335.42, exact mass =
335.18 g·mol–1): calcd. C 78.78, H 7.81, N 4.18%; found C 78.33, H
7.82, N 4.29%. MS (EI, 90 eV) m/z (%): 335 (100) [M+], 135 (26,
M+ - Ph2PNH).
P-tert-Butyl(diphenylphosphanyl)amino-C-bis(trimethylsilyl)phos-
phaalkene (3a): tButylaminodiphenylphosphane 1a (0.2565 g,
1 mmol) in 10 mL THF and LDA (0.5 mL of a 2 M solution in THF-
heptane-ethylbenzene, 1 mmol) led to 2a (δ = 31P = 49.0 ppm), which
reacted with 0.2245 g (1 mmol) of (Me3Si)2C=PCl to give 387 g
(87%) of 3a as a brown oil. Single crystals of 3a were obtained by
storing a pentane solution at low temperature. 1H NMR (C6D6,
300 MHz): δ = 7.8–7–02 ppm (m, 10, Ph), 1.5 (s, 9 H, tBu), 0.2 [d, 9
H, 4J(P,H) = 2.6 Hz, SiMe3], 0.0 (s, 9 H, SiMe3). 13C NMR (C6D6,
75.46 MHz): δ = 189.5 [d, 1J(P,C) = 97.7 Hz, C=P], 140.0 [d,d, 1J(P,C)
Ph2PN(H)CMe3 (1d): A solution of C-triphenylmethylamine (1.51 g,
5,81 mmol) in 10 mL THF was treated at –50 °C dropwise with n-
butyllithium (2.5 m solution in hexane, 2.3 mL, 5.81 mmol). The
stirred solution was allowed to warm up to room temperature and after
2 h the resulting solution was added at –40 °C dropwise to chlorodi-
phenylphosphane (1.28 g, 5.81 mol) in 10 mL THF. After warming up
to room temperature the lithium salt residue was removed by filtration.
Evaporation of the solvent at reduced pressure provided 1d (2.07 g,
3
= 18.2, J(P,C) = 2.6 Hz, ipso-C, Ph], 135.0 [d,d, 2J(P,C) = 23, 4J(P,C)
1
81%) as a yellowish solid, m.p. 118–120 °C. H NMR (200.1 MHz,
3
= 4.8 Hz, o-C, Ph], 128.6 (s, p-C, Ph), 128.1 (d, J(P,C) = 6.6 Hz, m-
C6D6): δ = 7.5–7.03 (multiplets, aryl H), 3.07 (s, H–N) ppm. 13C
NMR (50.32 MHz, C6D6): δ = 146.8 [d, J(C,P) = 3.5 Hz], 142.1 [d,
J(C,P) = 12.7 Hz], 130.6 [d, J(C,P) = 20.8 Hz], 128.3 [d, J(C,P) =
2.3 Hz], 127.5 [d, J(C,P) = 8.9 Hz], 127.1 (s), 125.9 (s), 70.5 [d, J(C,P)
= 18.8 Hz]. 31P NMR (81.02 MHz, C6D6): δ = 27.1 ppm. C31H26NP
(M = 443.52): calcd. C 83.95, H 5.91. N 3.16%; found C 80.95, H
5.90, N 3.18%.
C, Ph), 59.4 [dd,, 2J(P,C) = 23, 2J(P,C) = 0.8 Hz, Cquart. tBu], 33.0 [d,d,
3J(P,C) = 10.5, 3J(P,C) = 4.1 Hz, CH3 (tBu)], 3.6 [d, 3J(P,C) = 16.8 Hz,
SiMe3], 2.8 [d, 3J(P,C)
=
2
3.3 Hz, SiMe3]. 31P NMR (C6D6,
2
121.5 MHz): δ = 372.9 [d, J(P,P) = 11.5 Hz, P = C], 44.4 [d, J(P,P)
= 11.5 Hz, PPh2]. 29Si NMR (C6D6, 59.6 MHz): δ = –3.7 [d, J(PSi)
2
2
= 41.7 Hz], –10.1 [d, J(PSi) = 10.6 Hz.]. MS (EI, 90 eV) m/z (%) =
445 (38) [M+], 372 (100, M – SiMe3), 316 (40, M – SiMe3, –tBu).
Ph2PN(H)(2,4,6-Me3C6H2) (1f): Similarly to the preparation of 1b, C23H37NP2Si2 (M = 445.67 g.·mol–1): calcd. C 61.99, H 8.37, N
chlorodiphenylphosphane (3.52 g, 15.97 mmol) in 75 mL pentane with
3.14%; found C 61.72, H 8.01, N 3.40%.
Z. Anorg. Allg. Chem. 2018, 381–390
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© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Journal of Inorganic and General Chemistry
ARTICLE
Zeitschrift für anorganische und allgemeine Chemie
Selenium Addition to P-1-Adamantyl(diphenylphosphanyl)amino-
C-bis(trimethylsilyl)phosphaalkene (3b): 3b was prepared as de-
scribed.[8a] A solution of 0.673 g (1.28 mmol) 3b in 5 mL CH2Cl2 was hexane) leading to 2h (δ = 31P = 42.4 ppm). This reacted with 1.67 g
phenylphosphane (1h) (2.5 g, 7.44 mmol) in 10 mL THF was metall-
ated with an equimolar amount of n-butyllithium (2.5 m solution in
added dropwise to a suspension of grey selenium (0.253 g, 3.2 mmol)
in 5 mL CH2Cl2. After 3 h 31P NMR confirmed the complete consump-
tion of 3b in favor of P-1-adamantyl[diphenyl(selenoxo)phosphor-
(7.44 mmol) (Me3Si)2C=PCl delivering a yellow impure oil that con-
tained, according to 31P NMR, about 60% of 3h, 20% of the starting
material 1h, and 20% of P-2,6-diisopropylphenylamino-C-bis(trime-
anyl]amino-C-bis(trimethylsilyl)phosphaalkene {1-Ada[Ph2P(=Se)]NP= thylsilyl)phosphaalkene. A few pale yellow crystals of 3h were grown
C(SiMe3)2, 3b=Se}. Removal of unconsumed selenium by filtration from a THF/pentane mixture. 31P NMR (C6D6, 81 MHz): δ = 335.8
and evaporation under high vacuum afforded
a
yellow solid
(s, br., P=C), and 58.8 (s, br., PPh2), 3h (about 60%), 316.5 (s, proba-
(0.733 g, 95%) containing 3b=Se. Solutions of 3b=Se in CDCl3 bly the DIPP-aminophosphaalkene, about 20%), 42. 9 (s, 1h, about
contained, by 31P NMR, about 10% of the decomposition products
1-Ada[Ph2P(= Se)]NH and [(Me3Si)2C=P]Se.[13]
20%).
P-tert-Butyl(diphenylphosphanyl)amino-C-bis(isopropyldimeth-
ylsilyl)phosphaalkene (4a): tButylaminodiphenylphosphane (1a)
(1.20 g, 4.66 mmol) in 10 mL THF reacted with LDA (2.4 mL of a
2M solution in THF-heptane-ethylbenzene, 4.8 mmol) to give 2a (δ =
31P = 49.7 ppm), which in turn reacted with (iPrMe2Si)2C=PCl (1.31 g,
4.66 mmol), yielding 2.0 g (85%) of 4a as a brown viscous oil. For
proposed 1H and 13C NMR assignments, see Scheme 5. 1H NMR
(300 MHz, C6D6): δ = 7.66–7.60 (m, aryl H i), 7.13–6.97 (m, aryl H
k, j), 1.46 (s, CH3, m), 1.21–1.09 (m, C-H, e, f), 0.99 [d, 5J(P,H) =
6.8 Hz, CH3, d], 0.81 [d, 5J(P,H) = 4.0 Hz, CH3, c], 0.21 [d, 4J(P,H) =
2.3 Hz, CH3Si b], 0.0 ppm (s, CH3Si a). 13C NMR (75.5 MHz, C6D6):
δ = 179.1, (d, d-like X-part of AMX, N = 98.7 Hz and 6 Hz, P=C, g),
139.4 [d, 1J(P,C) = 21.0 Hz, aryl-C, h], 134.1 [d, d-like X-part of
1
3b=Se: H NMR (CDCl3, 300 MHz): δ = 7.9–7.24 (aryl multiplets),
2.46 [s, br., CH2 (Ada)], 1.86 [br., CH (Ada)], 1.56 [m, CH2 (Ada)],
0.37 (s, SiMe3), 0.04 [d, 3J(P,H) = 3.0 Hz, SiMe3). 13C NMR (CDCl3,
75 MHz): δ = 183.4 [d, d, 1J(P,C) = 101.8, 3J(P,C) = 4.6 Hz, C=P],
135.9 [d, d, 1J(P,C) = 87.4, 3J(P,C) = 1.8 Hz, ipso-C, Se = PPh2], 133.8
[d, d, 2J(P,C) = 10.9, 4J(P,C) = 4.6 Hz, o-C, Se = PPh2], 131.5 [d,
4J(P,C) = 2.0 Hz, p-C, Se = PPh2], 128.1 [d, J(P,C) = 12.9 Hz, m-C,
Se = PPh2], 65.5 (s, br., C-P, Ada), 44.2 [pseudo-t, N(1–3) = 9.3 Hz,
CH2, Ada], 36.0 (s, CH2, Ada), 30.1 (s, CH, Ada), 3.4 [d, 3J(P,C) =
3.4 Hz, SiMe3], 2.9 [d, J(P,C) = 18.3 Hz, SiMe3]. 31P NMR (CDCl3,
121 MHz): δ = 350.4 (s, P=C), 45.7 [s, J(SeP) = 742 Hz, Se=PPh3].
29Si NMR (CDCl3, 59 MHz): δ = –4.4 [d, 2J(PSi) = 45.2 Hz, –10.3
[d, J(PSi) = 9.7 Hz] ppm. C29H43NP2SeSi2 (M = 602.16, exact mass
602.74): calcd. C 57.79, H 7.19, N 2.32%; found C 57.79, H 7.32, N
2.45%. MS (EI, 90 eV) m/z (%) = 415 (10, Ph2PSeNHAda+), 369 (36,
M+ – Ph2Se), 73 (100, SiMe3+).
3
3
3
2
3
AMX, N = 22.7 Hz and 3.6 Hz, aryl-C, i), 128.9 [d, J(P,C) = 6.4 Hz,
aryl-C, j], 128.3 (s, aryl p-C, k), 60.3 [d, d, 2J(P,C) = 16.8 Hz and
3
1.6 Hz, N-C, l], 32.8 [d, d-like X-part of AMX, J(P,C) = 8.4 Hz and
5.2 Hz, CH3 (tBu), m], 17.9 [s, CH3 (iPr), c], 17.8 [d, 4J(P,C) = 2.2 Hz,
CH3 (iPr), d], 15.4 [d, 3J(P,C) = 12.6 Hz, CH (iPr), f], 14.3 [s, CH
(iPr), e), –0.4 [d, 2J(P,C) = 18.6, CH3Si, b), –1.7 (s, CH3Si, a). 29Si
NMR (59.6 MHz, C6D6): δ = 1.8 [d, 2J(PSi) = 35.2 Hz], –4.4 [d,
2J(PSi) = 9.5 Hz]. 31P NMR (121.5 MHz, C6D6): δ = 382.3 (d) and
47.0 [d, 2J(P,P) = 6.6 Hz]. C27H45NP2Si2 (M = 501.77; exact mass
501.26 g.mol–1): calcd. C 64.63, H 9.04, N 2.79%; found C 62.99, H
8.95, N 2.70%. MS (EI, 90 eV) m/z (%); 501 (4) [M+], 400 (100,
M+ – iPrMe2Si), 344 (16, M+ – iPrMe2Si, – C4H8).
1-Ada[Ph2P(=Se)]NH: 31P NMR (CDCl3, 121 MHz): δ = 44.8 [s,
1J(SeP) = 752.1 Hz. 77Se NMR (CDCl3, 57 MHz): δ = –185.6 [d,
1J(SeP) = 752.2 Hz] ppm. C22H26NPSe (M = 414.38, exact mass
415.10): calcd. C 63.77, H 6.32, N 3.38%; found C 63.12, H 6.11,
N 3.35%. MS (EI, 90 eV) m/z (%) = 415 (100) [M+], 334 (36)
[M+ – Se].
P-(2,4,6-Tri-tert-butylphenyl)(diphenylphosphanyl)amino-C-bis-
(trimethylsilyl)phosphaalkene (3g): 2,4,6-Tri-tert-butylphenylamino-
diphenylphosphane (1g) (1.8 g, 4.05 mmol) in 10 mL THF reacted
with an equimolar amount of LDA (2.1 mL of a 2 M solution in THF-
heptane-ethylbenzene, 4.2 mmol) to give 2g (δ = 31P = 58.0 ppm),
which in turn reacted with 0.9 g (4.05 mmol) (Me3Si)2C=PCl, furnish-
ing 3g (2.3 g, 90%) as a yellowish solid. 1H NMR (C6D6, 300 MHz):
δ = 8.04–6.95 (m, aromatic H), 1.65 [s,o-tBu (Mes*)], 1.35 [s, p-tBu
P-1-Adamantyl(diphenylphosphanyl)amino-C-bis(isopropyldi-
methylsilyl)phosphaalkene (4b): 1-Adamantylaminodiphenylphos-
phane (1b) (0.93 g, 2.76 mmol) in 10 mL THF reacted with LDA
(1.4 mL of a 2 M solution in THF-heptane-ethylbenzene, 2.8 mmol) to
give 2b (δ = 31P = 45.3 ppm), which in turn reacted with (iPrMe2Si)
2C=PCl (0.78 g, 2.76 mmol), yielding 1.3 g (82%) of 4b as a yellow
solid, m.p. 97–98 °C. Recrystallization from hexane at –20 °C gave
yellow crystals suitable for X-ray diffraction. 1H NMR (300 MHz,
4
(Mes*)], 0.62 [d, J(P,H) = 3.5 Hz, SiMe3], 0.0 (s, SiMe3). 13C NMR
(C6D6, 75.46 MHz): δ = 147.6 [d, 3J(P,C) = 4.1 Hz, o-C (Mes*)], 147.6
2
(s, p-C, Mes*), 143.1 [d,d, J(P,C) = 16.7 and 9.9 Hz, ipso-C (Mes*), C6D6): δ = 7.73–7.68 (m, aryl H i), 7.10–6.94 (m, aryl H k, j), 1.92
139.9 [d,d, 1J(P,C) = 29.2, 3J(P,C) = 6.9 Hz, ipso-C (PPh2)],135.3 [d,d,
2J(P,C) = 28.9, 4J(P,C) = 8.3 Hz], 129.4 (s, p-C, PPh2], 128.1 [d,
(s, Ada,), 1.51–1.39 (m, Ada,), 1.13–0.95 (m, Ada), 1.13–0.95 (m, C-
H, c, e, f), 0.83 [d, 5J(P,H) = 7.2 Hz, CH3, d], 0.20 [d, 4J(P,H) = 2.5 Hz,
CH3Si b), 0.0 ppm (s, CH3Si a). 13C NMR (75.5 MHz, C6D6): δ =
4
3J(P,C) = 9.3 Hz, m-C, PPh2], 126.8 [d, J(P,C) = 2.3 Hz, m-C, Mes*],
3
1
37.9 [d, J(P,C) = 0.9 Hz, o-C], 34.7 [t, line distance 2.6 Hz, CH3 (o-
183.7, (d, J = 102.6 Hz, P = C, g), 139.8 [d, d-like X-part of AMX,
4
tBu, Mes*)], 34.5 [s, p-tBu, Cquart.], 31.1 [s, CH3, p-tBu (Mes*)], 5.0
2J(P,C) = 19.1, J(P,C) = 2.5 Hz, aryl-C, h], 134.6 [d, d-like X-part of
[d, 3J(P,C) = 20.3 Hz, SiMe3], 3.3 [d, 3J(P,C) = 2.2 Hz, SiMe3]. 31P AMX, J(P,C) = 22.9, J(P,C) = 4.5 Hz, aryl-C, i], 128.2 (s, aryl p-C,
2
4
2
3
2
NMR (C6D6, 121.5 MHz): δ = 337.7 [d, J(P,P) = 21 Hz, P = C, I = k), 127.8 [d, J(P,C) = 6.5 Hz, aryl-C, j], 61.1 [d, J (PC) = 19.6 Hz,
2
ca. 1.5], 330.5 [d, 2J(P,P) = 57.1 Hz, P = C, I = ca. 7], 74.0 [d, J(P,P) N-C, l], 45.8 [d, d-like X-part of AMX, 3J = 10.7 Hz and 4.0 Hz, Ada],
2
4
= 57.1 Hz, PPh2, I = ca. 13.5],], 55.1 [d, J(P,P) = 20.9 Hz, PPh2, I = 36.3 (s, Ada), 30.9 (s, Ada), 18.0 [s, CH3 (iPr), c], 17.8 [d, J(P,C) =
3
ca. 2.6].C37H57NP2Si2 [M = 633.97 (exact mass 633.35)]. MS (EI,
2.8 Hz, CH3 (iPr), d], 15.5 [d, J(P,C) = 13.6 Hz, CH (iPr), f], 14.6 [s,
90 eV) m/z (%): 633 (44) [M+], 618 (35, M+– CH3), 576 (20,
CH (iPr), e], –0.3 [d, 2J(P,C) = 17.8, CH3Si, b], –1.6 (s, CH3Si, a).
M+ – tBu), 448 (64, M+ – PPh2), 388 (30, M+ – Mes), 73 (100, SiMe3). 29Si NMR (59.6 MHz, C6D6): δ = 1.5 [d, J(PSi) = 36.0 Hz], –4.7 [d,
2
2J(PSi) = 9.7 Hz]. 31P NMR (121.5 MHz, C6D6): δ = 385.7 (d) and
P-(2,6-Diisopropylphenyl)(diphenylphosphanyl)amino-C-bis(tri-
methylsilyl)phosphaalkene (3h): P-2,6-Diisopropylphenylaminodi-
38.3 [d, 2J(P,P) = 10.0 Hz] ppm. C33H51NP2Si2 (M = 579.99, exact
mass = 359.30 g·mol–1): calcd. C 68.35, H 8.86, N 2.42%; found C
Z. Anorg. Allg. Chem. 2018, 381–390
www.zaac.wiley-vch.de 387
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Journal of Inorganic and General Chemistry
ARTICLE
Zeitschrift für anorganische und allgemeine Chemie
2
66.51, H 8.80, N 2.45%. MS (EI, 90eV) m/z (%) = 579 (4) [M+], 564 38.2 Hz], –4.6 [d, J(PSi) = 9.4 Hz]. 31P NMR (81 MHz, C6D6): δ =
(2, M+ –CH3), 478 (100, M+ – iPrMe2Si).
351.3 [d, 2J(P,P) = 67.5 Hz], 60.9 [d, 2J(P,P) = 67.5 Hz]. C29H41NP2Si2
(M = 521.76, exact mass = 521.23): calcd. C 66.76, H 7.92, N 2.68%;
found C 65.78, H 7.92, N 2.99%. MS (EI, 90 eV) m/z (%): 521 (7)
[M+], 506 (2, M+ – CH3), 478 (3, M+ – iPr), 420 (100, M+. iPrMe2Si).
P-Isopropyl(diphenylphosphanyl)amino-C-bis(isopropyldimeth-
ylsilyl)phosphaalkene (4c): Isopropylaminodiphenylphosphane (1c)
(1.04 g, 4.26 mmol) in 10 mL THF reacted with LDA (2.2 mL of a
2 M solution in THF-heptane-ethylbenzene, 4.4 mmol) to give 2c (δ =
31P = 41.9 ppm), which in turn reacted with (iPrMe2Si)2C=PCl (1.2 g,
P-2,4,6-Trimethylphenyl(diphenylphosphanyl)amino-C-bis(iso-
propyldimethylsilyl)phosphaalkene (4f): 2,4,6-Trimethylphenylami-
nodiphenylphosphane 1f (0.68 g, 2.14 mmol) in 10 mL THF reacted
with LDA (1.1 mL of a 2 M solution in THF-heptane-ethylbenzene,
2.2 mmol) to give 2e (δ = 31P = 49.9 ppm), which in turn reacted
with (iPrMe2Si)2C=PCl (0.6 g, 2.14 mmol), forming, according to 31ЈP
NMR, 4f as the main product and the starting material 1f (δ = 31P =
36.5 ppm) as impurity. The attempted purification of 4f failed since
increasing amounts of 1f were observed. 4f: 31P NMR (C6D6,
81 MHz) δ = 331 ppm and 64 ppm [broad signals, 2J(P,P) not re-
solved].
1
4.26 mmol), yielding 1.77 g (86%) of 4c as a brown viscous oil. H
NMR (300 MHz, C6D6): δ = 7.30–7.23 (m, aryl H i), 6.94–6.82 (m,
aryl H k, j), 4.12–3.97 (m, iPr-N), 1.31–1.22 (m, iPr), 1.03 [d, J(P,H)
= 6.6 Hz, iPr], 0.76 [d, J(P,H) = 7.6 Hz, iPr], 0.08 (s, CH3Si a), - 0.01
[d, 4J(P,H) = 3.7 Hz, CH3Si b]. 13C NMR (75.5 MHz, C6D6): δ =
1
3
144.3, [d, d-like X-part of AMX, J(P,C) = 91.0, J(P,C) = 4.6 Hz, P
= C, g], 139.3 [d, d-like X-part of AMX, 1J(P,C) = 18.3, 2J(P,C) =
4.6 Hz, aryl-C, h], 132.5 [d, d-like X-part of AMX, 2J(P,C) = 21.4,
4J(P,C) = 2.4 Hz, aryl-C, i], 128.6 (s, aryl p-C, k), 128.6 [d, J(P,C) =
3
2
6.1 Hz, aryl-C, j], 53.0 [d, J (PC) = 13.6 Hz, N-C, l], 24.5 [d, d-like
P-(2,4,6-Tri-tert-butylphenyl)(diphenylphosphanyl)amino-C-bis-
(isopropyldimethylsilyl)phosphaalkene (4g): 2,4,6-Tri-tert-butyl-
phenylaminodiphenylphosphane (1g) (1.58 g, 3.54 mmol) in 10 mL
THF reacted with an equimolar amount of LDA (1.8 mL of a 2M
solution in THF-heptane-ethylbenzene, 3.6 mmol) to give 2g (δ = 31P
= 58.3 ppm). This in turn reacted with (iPrMe2Si)2C=PCl (1.0 g,
3.54 mmol) to form 4g as a mixture of isomers (conformers) also con-
taining the aminophosphaalkene (iPrMe2Si)2C=PN(Mes*)PPh2 (δ =
31P = 325 ppm).[8] One of the isomers of 4g was crystallized from a
mixture of hexane and acetonitrile at –20 °C, but NMR spectroscopic
data could not be determined because of the small amount of crystals.
4g (mixture of rotamers): 31P NMR (81 MHz, C6D6): δ = 341.2 and
72.6 [d, 2J(P,P) = 67.5 Hz, about 60% signal intensity], 337.8 and 50.2
[d, 2J(P,P) = 67.5 Hz, about 40% signal intensity]. MS (EI, 90 eV) m/z
(%) 689 (2.2) [M+], 674 (6.8, M+ – CH3), 646 (12, M+ – C3H7), 444
(42, M+ – Mes*).
3
X-part of AMX, J(P,C) = 8.9 Hz and 5.2 Hz, CH3 (iPr-N), m], 17.8
[s, CH3 (iPr), c], 17.7 [d, 4J(P,C) = 2.2 Hz, CH3 (iPr), d], 15.2 [d,
3J(P,C) = 10.2 Hz, CH (iPr), f], 13.9 [d, d-like X-part of AMX, J =
2
5.7 Hz and 2.1 Hz, CH (iPr), e], –0.4 (s, CH3Si, a), –0.6 [d, J(P,C) =
18.6, CH3Si, b]. 29Si NMR (59.6 MHz, C6D6): δ = 3.1 [d, J(PSi) =
2
2
40.1 Hz], –5.6 [d, J(PSi) = 10.7 Hz]. 31P NMR (121.5 MHz, C6D6):
δ = 343 [d, 2J(P,P) = 13.8 Hz, P = C], 44 [br., 2J(P,P) not resolved,
PPh2] ppm.
P-Triphenylmethyl(diphenylphosphanyl)amino-C-bis(isopropyl-
dimethylsilyl)phosphaalkene (4d): Triphenylmethylaminodiphenyl-
phosphane 1d (0.52 g, 1.17 mmol) in 10 mL THF reacted with LDA
(0.6 mL of a 2 M solution in THF-heptane-ethylbenzene, 1.2 mmol)
to give 2d (δ = 31P = 53.5 ppm), which in turn reacted with
(iPrMe2Si)2C=PCl (0.33 g, 1.17 mmol), yielding a yellowish oil. Ac-
cording to 31P NMR (two sets of AX patterns) this contains two phos-
phanylamino phosphaalkene species (about 60% and 35% of the sig-
nal intensity), accompanied by small amounts of the aminophosphaalk-
ene (iPrMe2Si)2C=PN(H)CPh3 [δ = 31P = 317.6 ppm (s); pure sample:
δ = 318 ppm][8] and of the aminophosphane 1d [δ = 31P = 27.5 ppm
(s)]. Purification of 4d was not achieved. 31P NMR (C6D6, 81 MHz):
4d: δ = 366.5 [d, 2J(P,P) = 32.8 Hz], 361.5 [d, 2J(P,P) = 40.0 Hz],
X-ray Crystallography: Crystal data are summarized in Table 3 and
Table 4. Crystals were mounted in inert oil on glass fibres and transfer-
red to the cold gas stream of an Oxford Diffraction Xcalibur A or (for
3h) Nova E diffractometer. Intensity measurements were performed
using monochromated Mo-Kα radiation or (for 3h) mirror-focussed Cu-
Kα radiation, respectively. Absorption corrections were based on multi-
scans. Structures were refined anisotropically on F2 using the program
SHELXL-97.[14] All NH hydrogens were refined freely; other
hydrogen atoms were included using a riding model or rigid methyl
groups. Exceptions and special features: Compound 3g crystallizes in
P212121, but the symmetry is close to Pnma. The structure was refined
as an enantiomeric twin, with a Flack parameter of 0.22(4). For com-
pound 4g, the SiMe2iPr group Si2, C6–10 was disordered over two
positions with relative occupations 0.835, 0.165(2). Appropriate simi-
larity restraints were used to improve refinement stability, but the di-
mensions of disordered groups should be interpreted with caution.
2
2
25.6 ppm [d, J(P,P) = 32.8 Hz], 15.4 ppm [d, J(P,P) = 40.0 Hz].
P-Phenyl(diphenylphosphanyl)amino-C-bis(isopropyldimethyl-
silyl)phosphaalkene (4e): Phenylaminodiphenylphosphane (1e)
(1.87 g, 6.75 mmol) in 10 mL THF reacted with LDA (1.4 mL of a
2 M solution in THF-heptane-ethylbenzene, 2.8 mmol) to give 2e (δ =
31P = 38.2 ppm), which in turn reacted with (iPrMe2Si)2C=PCl (1.9 g,
6.75 mmol) to yield 4e (2.94 g, 84%) as a yellow solid (m.p. 81–
82 °C). 1H NMR (300 MHz, C6D6): δ = 7.74–6.85 (m, several mul-
tiplets from aryl protons), 1.09–0.94 (m, C-H, iPr, c, d, e, f, d), 0.38
[d, 4J(P,H) = 3.6 Hz, CH3Si b), 0.0 ppm (s, CH3Si a). 13C NMR
(75.5 MHz, C6D6): δ = 163.8, (d, d-like X-part of AMX, 1J(P,C) = 93,
3J(P,C) = 7.5 Hz, g), 150.5 (d, d-like X-part of AMX, J(P,C) = 10.7
We reported the structure of compound 3b in a short communication,
CCDC-731434.[3] Herein it is discussed in detail for the first time.
and 5.7 Hz, aryl-C, l), 138.4 (d, d-like X-part of AMX, J(P,C) = 19.9 Crystallographic data (excluding structure factors) for the structures in
and 5.4 Hz, h), 133.8 (d, d-like X-part of AMX, J(P,C) = 21.5 and 2.8, this paper have been deposited with the Cambridge Crystallographic
i), 129.6 [d, J(P,C) = 10.5 Hz, aryl-C], 128.9 [d, J(P,C) = 6.5 Hz, aryl- Data Centre, CCDC, 12 Union Road, Cambridge CB21EZ, UK. Copies
C, j], 127.1 (d, d-like X-part of AMX, N = 7.1 and 1.6 Hz, aryl-C), of the data can be obtained free of charge on quoting the depository
124.8 [d, J(P,C) = 1.6 Hz, aryl-C], 18.34 [s, CH3 (iPr), c], 18.3 [s, CH3 numbers CCDC-1055077 (1b), CCDC-1055311 (1f), CCDC-1055310
3
(iPr), d], 15.5 [d, J(P,C) = 9.4 Hz, CH (iPr), f], 13.2 [s, CH (iPr), e), [1f(P=O)], CCDC-1054304 (3a), CCDC-1054305 (3g), CCDC-
–0.5 [d, 2J(P,C) = 20.9, CH3Si, b), –1.9 (s, CH3Si, a). 29Si NMR
1054302 (3h), CCDC-1055308 (4b), and CCDC-1055309 (4g). (Fax:
+44-1223-336-033; E-Mail: deposit@ccdc.cam.ac.uk, http://www.
ccdc.cam.ac.uk)
2
2
(59.6 MHz, C6D6): δ = 2.3 [d, J(PSi) = 38.2 Hz], –4.6 [d, J(PSi) =
2
9.4 Hz]. 29Si NMR (59.6 MHz, C6D6): δ = [ppm] = 2.3 [d, J(PSi) =
Z. Anorg. Allg. Chem. 2018, 381–390
www.zaac.wiley-vch.de 388
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Journal of Inorganic and General Chemistry
ARTICLE
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Table 3. X-ray crystallographic details for 1b, 1f, 1f(P=O), and 3a.
1b
1f
1f(P=O)
3a
Chemical formula
Mr
C22H26NP
335.41
C21H22NP
319.37
C21H22NOP
335.37
C23H37NP2Si2
445.66
Crystal system
Space group
Temperature /K
a /Å
b /Å
c /Å
triclinic
P1
100
7.5097(3)
11.1582(5)
12.2429(5)
101.028(3)
105.671(3)
107.589(5)
898.99
monoclinic
P21/n
100
15.3841(3)
4.61047(8)
25.9647(4)
90
107.566(2)
90
triclinic
P1
100
9.5330(6)
10.1794(8)
20.0680(10)
76.972(4)
77.500(4)
70.086(6)
1763.0
triclinic
P1
100
¯
¯
¯
9.9254(2)
10.0539(3)
14.7695(2)
72.141(2)
80.766(2)
67.700(3)
1296.27
1.142
α /°
β /°
γ /°
V /Å3
1755.75
1.208
4
dcalc /g·cm–3
Z
1.239
2
1.264
4
2
F(000)
360
0.16
680
0.16
712
0.16
480
0.27
μ /mm–1
Crystal size /mm
Transmissions
2θmax /°
0.10ϫ0.09ϫ0.07
No abs. corr.
52.7 (Mo-Kα)
0.26ϫ0.23ϫ0.19
0.96–1.00
56.6 (Mo-Kα)
54206, 4342
0.025
0.14ϫ0.13ϫ0.06
0.99–1.00
52.7 (Mo-Kα)
46268, 7201
0.062
0.16ϫ0.14ϫ0.11
0.97–1.00
56.6 (Mo-Kα)
25526, 5977
0.032
No. of measured and independent reflections 21740, 3675
Rint
0.040
0.062, 0.033
0.88
wR(F2) all refl., R1 [F Ͼ 4σ(F)]
0.097, 0.034
1.07
0.085, 0.040
0.82
0.077, 0.031
0.95
S(F2)
No. of parameters / restraints
Δρmax, min /e·Å–3
221 / 0
0.29, –0.31
215 / 0
0.45, –0.21
447 / 0
0.33, –0.36
262 / 0
0.48, –0.20
Table 4. X-ray crystallographic details for 3g, 3h, 4b and 4g.
3g
3h
4b
4g
Chemical formula
Mr
C37H57NP2Si2
633.96
C31H45NP2Si2
549.80
C33H51NP2Si2
579.87
C41H65NP2Si2
690.06
Crystal system
Space group
Temperature /K
a /Å
b /Å
c /Å
orthorhombic
P212121
100
11.2381(2)
15.7876(2)
21.0360(2)
90
monoclinic
P21/n
100
8.6563(2)
18.6668(2)
20.1109(4)
90
monoclinic
P21/n
100
10.3169(4)
33.8246(6)
10.6425(4)
90
monoclinic
P21/c
100
21.9125(4)
15.8146(2)
11.9245(2)
90
α /°
β /°
90
90
3732.26
1.128
4
98.159(2)
90
3216.74
1.135
118.456(4)
90
3262.38
1.181
95.475(2)
90
4115.12
1.114
γ /°
V /Å3
dcalc /g·cm–3
Z
4
4
4
F(000)
1376
0.21
0.27ϫ0.23ϫ0.22
0.98–1.00
58.4 (Mo-Kα)
1184
2.1
1256
0.23
1504
0.19
μ /mm–1
Crystal size /mm
Transmissions
2θmax /°
0.18ϫ0.15ϫ0.15
0.66–1.00
152 (Cu-Kα)
36226, 6595
0.032
0.25ϫ0.13ϫ0.12
0.99–1.00
56.6 (Mo-Kα)
84436, 8086
0.036
0.35ϫ0.30ϫ0.15
0.96–1.00
56.6 (Mo-Kα)
135264, 10180
0.037
No. of measured and independent reflections 76591, 9265
Rint
0.024
0.071, 0.026
1.00
wR(F2) all refl., R1 [F Ͼ 4σ(F)]
0.094, 0.034
1.04
0.079, 0.030
0.99
0.081, 0.030
1.02
S(F2)
No. of parameters / restraints
Δρmax, min /e·Å–3
395 / 0
0.28, –0.19
335 / 0
0.34, –0.30
351 / 0
0.41, –0.18
457 / 102
0.35, –0.26
Supporting Information (see footnote on the first page of this article):
contains the structures of 1b, 1f, and of 1f(P=O) (Figs. S1 – S3) as
well as a consideration of conformational influences on J(PP)
Keywords: Phosphaalkenes; Phosphane ligands; Iminophos-
phanes; π-interaction; Conformational analysis
2
(Scheme S1).
References
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We thank the COST programme CM0802 “PhosSciNet” and the Deut-
sche Forschungsgemeinschaft (MO290/28–1) for financial support.
Z. Anorg. Allg. Chem. 2018, 381–390
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© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Journal of Inorganic and General Chemistry
ARTICLE
Zeitschrift für anorganische und allgemeine Chemie
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Received: December 14, 2017
Published online: April 10, 2018
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