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Chelate Ligand-Controlled 1-2 Change of Coordination in Amino(imino)phosphane Ligands and Their Conversion into a Nickelaazadiphosphetidine.

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Chelate Ligand-Controlled q'-q2 Change of
Coordination in Amino(imino)phosphane Ligands
and Their Conversion into a Nickelaazadiphosphetidine
By Otto J . Scherer,* Richard Walter and
William S . Sheldrick
Amino(imino)phosphanes, compounds containing triply
bonding phosphorus of coordination number two, are versatile ligands.".*'
Reaction of the nickel complex 1 and the amino(imino)phosphane 2 (molar ratio 1 :3) affords the synthetic
building block 3 with terminal P-coordination of the ligand 2 . The tridentate ligand 7 reacts with 3 such that the
q'-type coordination of the amino(imin0)phosphane ligand is retained in 4, whereas in the reaction of 3 with
dppe to give 5 , a change of coordination from the q'- to
the q2-type of coordination takes place.[315 is the first example of a compound containing a classical side-on coordinated P=N ligand.'4.121
The reaction is steered in a completely different fashion by bpy. Two P=N functions form,
via coupling of a P-N bond, the nickelaazadiphosphetidine 6 , the first P2N2four-membered ringf5]in which a nitrogen atom is replaced by a metal atom (Ni). 3, 4, and 6
form dark red to brownish-black crystals, while 5 forms
yellowish-orange crystals;[61in each case the crystals are
readily soluble in benzene, moderately (3 and 4 readily)
soluble in pentane, and only very sparingly soluble in acetonitrile.
The "P('H}-NMR signal (Table 1) of the nbonded
-P=N- ligand in 5 is shifted upfield by about 260 ppm
compared to that of free 2 (6=327), the largest shift so far
observed in the case of coordinated amino(imino)phosphane ligands (cf. the upfield shift of ca. 155pm in the
case of p3-$ coordination[*]).One of the two R2N groups
of 6 exhibits hindered P-N rotation at room temperature.
The crystal structure analysis"' shows that 2 is side-on
coordinated in 5 (Fig. 1) and that its trans arrangement at
Table 1. N M R data of 3-6 (6, J [Hzl).
3 0.40 (s, 81 H)
4 0.43 (s, 18 Hj
0.58 (s, 9 H)
5 0.54 (d, I8H) [c]
4J(PH)= 1 .0
0.49 (s, 9 H)
6
0.36 (s, 9 H), 0.54 (d, 9 H)
4J(PHj= 2.8,
0.57 (s, 9 H), 0.62 ( s , 9 H),
0.76 (s, 18H)
262.4 (s)
245.2 (q), 6.2 (d), 2J(PPj= 30.0
ABC spin system
PA(dppe) 42.3 (dd), Ps(dppe) 51.6 (dd)
P,(PN) 65.8 (d, br.)
assumption: 'J(PPC trans) > 'J(PP< cis),
2J(PAP~)=
55.6, 'J(PaPc)= 25.9,
'J(P.Pc)=8.3
180.5 (s, A'-P), -4.8 (s, X - P )
[a] 200 MHz, 293 K, C7D8, TMS int., only the signals of PN ligand(s) are
quoted. [b] 81.01 MHz, 293 K, Cell6, 85% H,PO, ext. [c] Dynamic NMR
spectroscopy: T, =213 K, A v = 58.3, A G (Tc)=43.0 kJ .mol- I.
+
the P=N-bond is retained. The characteristic structural
data of the free ligand 2 (P=N 1.545(2), P-N 1.674(1) A,
NPN 108.4(1), PNSi 129.9(1)0[81)
are changed by the coordination as follows: P=N(P!-N2) is about 0.101 longer,
P-N(P1-N1) about 0.063 A longer. The NI-PI-N2 angle, with a value of 109.1(1)O, remains virtually unchanged;
Pl-N2-Si2 (125.2(2)") is ca. 5" smaller. The Ni-P distance differs only very slightly from that of the side-on
coordinated R-P=P-R
ligand to the NLL9'The bending
angles between P1,N2 and the planes Si2,N2,P1 and
NI,PI,N2 away from the nickel atom are 42.3" and 12.3",
respectively. Ni is almost planar coordinated (dihedral angle PI,Nil,N2/P3,Nil,P4 3.4").
In the case of 6 (Fig. 2) the crystal structure data['] indicate a somewhat more pronounced tetrahedral distortion
(PI,Nil,P2/NS,Nil,N6 8.8 "). The ring-P-N distances and
angles
are comparable with those
of trans(R2N-PN-R)2,"01 the dimer of 2, whereas the corresponding exocyclic distances and angles lie in the normal
range found for diazadiphosphetidines.''] The N2-Si2
A
4
3 R.$-P=NR
,NR2
P=NR
2
Ni(cod)2 A
1
-2 COD
3
P
Ph2
NR,
R = SiMes
COD: 1,5 C y c l o o c t a d i e n e
,\3
5
I
dppe: Ph2PCH,CH,PPh2
bp y : 2.2' -bipyridine
Q..
R*\p/NR,
/ \
-\
/N-R
R2NNP
6
[*I
Prof. I l r . 0. J. Scherer, Dipl.-Chem. R. Walter, Prof. Dr. W. S. Sheldrick
Fachbereich Chemie der Universitat
Erwin-Schrodinger-Strasse,D-6750 Kaiserslautern (FRG)
Angew. Chem. lnr. Ed. Engl. 24 (1985)No. 6
0 VCH Verlagsgesellschaji mbH. 0-6940 Weinheim. 1985
0570-0833/85/0606-0525 0 02.50/0
525
bond with a length of 1.677(3) A, is distinctlyoshorter than
the other Si-N bonds (average length 1.759 A).
Received: March 4, 1985 [Z 1203 IE]
German version: Angew. Chem. 97 (1985) 525
CAS Registry numbers:
1, 1295-35-8: 2, 50732-21-3; 3, 96502-46-4; 4, 96482-91-4; 5, 96482-92-7; 6,
96532-15-9.
Fig. I.Structure of 5 in the crystal. Selected bond lengths [A] and angles ["I
(see also text): Nil-PI 2.231(1), Nil-P3 2.192(1), Nil-P42.126(1), Nil-N2
1.908(2), PI-NI 1.737(2), Pl-N2 1.646(2), N2-Si2 1.705(2), NI-Sill
1.756(2), N1 -Si 12 1.759(2): PI -Nil -P4 108.66(4), PI-Nil -N2 46.05(7),
PI-N2-Nil
77.4(1), Nil-PI-N2
56.58(9), N2-Nil-P3
114.43(7),
P3-Nil-P490.80(4), PIbN2-Si2 125.2(2), N2-P1-NI 109.1(1), sum of angles at NI 360.0.
Fig. 2. Structure of 6 i n ~ t h ecrystal (methyl groups are omitted for clarity).
Selected bond lengths [A] and angles ["I (see also text): Nil-PI 2.160(1),
Nil-P2 2.201(1), Nil-N5 1.978(3), Nil-N6 1.976(3), PI-NI 1.738(3).
PI-N2 1.556(3), PI-N3 1.700(3), P2-N3 1.772(3), P2-N4 1.759(3), Si2-N2
1.677(3), Si-N (average value, amine N-atoms) 1.759; PI-Nil-P2 73.75(2),
l02.7( I), P2-Nil -N5
102.3( I), N5-Nil -N6
81.2(2),
PI-Ni I -N6
PI-N3-P2 97.8(2), Nil-Pl-N3 95.4(1), Nil-P2-N3 92.0(1), Nl-PI-N2
102.9(2), PI-N2-Si2
154.8. Sum of angles at NI 359.8, N3 358.0, N4
360.0.
526
0 VCH Verlagsqesellschaji mbH, 0-6940 Weinheim, 1985
[I]0. J. Scherer, Nachr. Chem. Tech. Lab. 32 (1984) 582.
121 0. J. Scherer, R. Walter, W. S. Sheldrick, Angew. Chem. 97 (1985) 132:
Angew. Chem. Int. Ed. Engl. 24 (1985) 115.
[3] Cf. also the q'-q*-equilibrium in the case of a phosphaalkene complex
of platinum: T. A. van der Knaap, F. Bickelhaupt, J . G. Kraaykamp, G.
van Koten, J. P. C. Bernards, H. T. Edzes, W. S. Veeman, E. de Boer, E.
J. Baerends, Urganometa//ics 3 (1984) 1804; H. W. Kroto, S. 1. Klein, M.
F. Meidine, J. F. Nixon, R. K. Harris, K. J. Packer, P. Reams, J . Organomet. Chem. 280 (1985) 281.
[4] Side-on coordination, -P=P-, review: A. H. Cowley, Ace. Chem. Res.
11 (1984) 386. -N=N-,
review: A. Albini, H. Kisch, Top. Curr. Chem.
65 (1976) 105.
[5] Recent reviews: a) 0. J. Scherer, Nuchr. Chem. Tech. Lab. 28 (1980) 392:
b) R. Keat, Top. Curr. Chem. 102 (1982) 89.
[6] Preparation of 3 - 6 : 3 : A solution of 2 [I I] (1 178 mg, 4.23 mmol) in
toluene (1 mL) was added dropwise at room temperature to a stirred
suspension of 1 (388 mg, 1.41 mmol) in toluene (4 mL) and the mixture
stirred for a further 20 min. Such solutions were then used for further
reactions. 3 crystallizes out (sometimes difficult) in 8 d at -78°C in the
form of red crystals. These were washed with 2 mL of cold toluene and
dried under vacuum (oil-pump). Yield 416mg (33O/0). 4 : I (262mg,
0.95 mmol) was allowed to react with 2 (796 mg, 2.85 mmol) in benzene-under the same conditions as for 3-and then the solution was
treated with 594 mg (0.95 mmol) of 7 at room temperature. The reaction
mixture was stirred for a further 20 min, the solvent and COD removed
in vacuo, and the residue recrystallized from 4 m L acetonitrile/l m L toluene at ca. -20°C (2 d). The reddish-black crystals thus obtained were
washed twice with 4 mL C H K N and dried in vacuo.rYield 705 mg
(77%). 5: 1 (280 mg, 1.02 mmol) and 2 (853 mg, 3.06 mmol) were allowed to react under the conditions described for 3 and the reaction
mixture was then treated with a solution of 404 mg (1.02 mmol) of dppe
in benzene (3 mL) at room temperature. The work-up procedure was the
same as in the case of 4 . The residue was treated with 10 mL pentane,
with stirring, *hereupon 5 precipitated as a yellow powder. Subsequent
washing of the precipitate with ca. 20 m L pentane and recrystallization
from CH2Cl2/CH,CN (1 : I , ca. -2O"C, 2 d) furnished 532 mg of 5
(71?'0). 6 : 1 (215 mg, 0.78 mmol) and 2 (453 mg, 2.34 mmol) were allowed to react, as described for 3, and then treated with 123 mg
(0.78 mmol) bpy at room temperature. After work-up-in the same way
as for 4- the brownish-black residue was taken up in 5 mL pentane and
allowed to stand for 1 d at -78°C. The brownish-black crystals that
aeparated out (yield 512 mg (85O,n) of 6) were recrystallized from toluene/acetonitrile (5:2, 3 d, ca. -20°C).
17) 5 : P2,/n, a = 11.543(3), b= 10.655(2), r=32.074(4) A, 8=91.87(2)",
2 = 4 , pcdlc=
1.24 g
5141 independent reflections, 3960 observed
(MoKn. F;>2.0a(F$), 2 8 5 4 5 " ) ; R=0.049, R,=0.042.
6: Pi,
a= 13.270(2), b= 14.185(2), c=ll.599(2)A, a=92.55(1), fl=91.61(1),
y=96.99(1)", 2 x 2 , P ~ . ~ , ' =1.18 g C I I - ~ .5843 independent reflections,
3754 observed (MoKn, F'I22.0o(F& 20545'); R=0.053, R,=0.041.
Further details of the crystal structure investigations are available on request from the Fachinformationszentrum Energie Physik Mathematik,
D-7514 Eggenstein-Leopoldshafen2 on quoting the depository number
CSD 51 282, the names of the authors, and the full citation of the journal.
181 S. Pohl, Chem. Ber. I12 (1979) 3159.
[Y] B. Deppisch, H. Schafer, Acra Crysdlogr. 8 3 8 (1982) 748; D. Fenske,
K. Merzweiler, Anqew. Chem. 96 (1984) 600; Angew. Chem. Int. Ed.
Engl. 23 (1984) 635.
[lo] E. Niecke, W. Flick, S. Pohl, Angew. Chem. 88 (1976) 305: Angew. Chern.
Int. Ed. Engl. 15 (1976) 309.
[ I l l 0. J. Scherer, N. Kuhn, Chem. Ber. 107 (1974) 2123.
(121 Nore added in proof: The oxidation of 5 with RN3 and selenium, respectively, affords (dppe)Ni[q'-(X=)P(=NR)(NR2)1, X=Se, NR, R=SiMei
with side-on coordination of the P=X moiety.
0570-0833/85/0606-0526 $ 02.50/0
Angew. Chem. I n t . Ed. Engl. 24 il98Sj No. 6
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thein, imine, change, coordination, phosphane, amin, controller, nickelaazadiphosphetidine, conversion, ligand, chelate
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