Phosphino-urea chemistry: Preparation and structure of chelate and P-N bond cleavage complexes

Article abstract of DOI:10.1039/a908153d

Reactions of Ph₂PNRC(E)NRPPh₂ proceed to give simple P,P chelate complexes when E = O but give the unexpected five-membered true heterocycle Pt[Ph₂PN(Me)C(NMeH)S] Cl₂ and an unusual six-membered Pd₂P<

Full text of DOI:10.1039/a908153d

View Article Online / Journal Homepage / Table of Contents for this issue
Phosphino-urea chemistry: preparation and structure of chelate and
P–N bond cleavage complexes
Alexandra M. Z. Slawin, Matthew Wainwright and J. Derek Woollins*
Department of Chemistry, University of St. Andrews, T he Purdie Building, Fife, UK
KY 16 9ST
L e t t e r
Received (in Strasbourg, France) 9th October 1999, Accepted 22nd November 1999
Reactions of Ph PNRC(E)NRPPh proceed to give simple P,P
plane, C(26) and C(27) are ]0.20 and [0.21 A from the
plane]. The P(1)ÈPdÈP(2) bite angle is 94.76(3)¡ and the inter-
nal angle at phosphorus and carbon is close to trigonal whilst
the PdÈPÈC angles are somewhat enlarged from trigonal.
Reaction of the N,N-dimethylthiourea-phosphine with
2
2
chelate complexes when E = O but give the unexpected
Ðve-membered true heterocycle Pt[Ph PN(Me)C(NMeH)S]Cl
2
2 2
2
and an unusual six-membered Pd P O ring when E = S. The
2
X-ray structures of three examples are reported.
Pt(cod)Cl in THF proceeds with PÈN bond cleavage in 90%
2
Urea derivatives of the type [Ph PNHC(E)NHPPh ] (E \ O,
yield to give the novel Ðve-membered “true heterocycleÏ 2 (i.e.,
2
2
S)1,2 have recently been developed and shown to chelate to a
range of late transition metals through both phosphorus and
chalcogen donor atoms. However, the strong H-bonding that
is a common feature of urea chemistry may limit the potential
of these systems. Here we report on the preparation of some
NR (R \ Me, Et) derivatives and their coordination chem-
istry, which proceeds as expected to give simple chelates as
well as giving products from PÈN bond cleavage for some
reactions. These products include a Ðve-membered “true
heterocycleÏ and a binuclear complex containing a Pd P O
a heterocycle in which every ring atom is di†erent) according
to eqn. (3).
2 2
2
ring. The X-ray structures of demonstrative examples are
reported.
According to a recent review there are very few fully charac-
terised examples of 5-membered true heterocycles,8 though
there is a report of a related PtSCNP heterocycle.9 The X-ray
structure of 2 reveals (Fig. 2) square planar coordination of
the platinum with the Ðve-membered PtPNCS ring being
almost perfectly planar [maximum deviation from the
Schmutzler et al.3h7 have reported on the synthesis and
properties of phosphine substituted urea/thiourea species.
Along with other routes they noted that reaction of
Me SiN(Me)CO(Me)NSiMe
with
Ph PCl
gives
3
3
2
N,N-(Ph P)N(Me)CO(Me)NPPh . Thus, treatment of N,N-
PtPNCSCl plane is 0.11 A for S(13) with N(2), C(14) and
2
2
2
dialkylurea or N,N-dialkylthiourea with Ph PCl and tri-
C(15) lying 0.05, 0.18 and [0.06 A from this plane]. The bond
2
ethylamine in dichloromethane gives the diphosphines in
lengths and angles within 2 are in the expected range. The
PtÈCl distances vary as a function of the trans element; within
the Ðve-membered PtPNCS heterocycle the PÈN and CÈN
70È80% yield according to eqn. (1).
Surprisingly, almost no coordination chemistry has been
described for these phosphines. Attempts to coordinate the
urea derivatives proved satisfactory in some cases; for
example, reaction of the urea derivatives with M(cod)Cl
(M \ Pd, Pt) gives the expected complexes quantitatively
according to eqn. (2).
2
Fig. 1 The X-ray structure of 1. Selected bond lengths (A) and angles
(¡): Pd(1)ÈCl(1) 2.3476(8), Pd(1)ÈCl(2) 2.342(1), Pd(1)ÈP(1) 2.2003(8),
Pd(1)ÈP(2) 2.2072(8), P(1)ÈN(1) 1.697(2), P(2)ÈN(2) 1.704(2), N(1)È
C(13) 1.380(4), N(2)ÈC(13) 1.377(4); Cl(1)ÈPd(1)ÈCl(2) 91.47(3), P(1)È
Pd(1)ÈP(2) 94.76(3), Pd(1)ÈP(1)ÈN(1) 118.19(9), Pd(1)ÈP(2)ÈN(2)
118.41(9), P(1)ÈN(1)ÈC(13) 132.6(2), P(2)ÈN(2)ÈC(13) 131.5(2), N(1)È
C(13)ÈN(2) 122.9(3), N(1)ÈC(13)ÈO(13) 118.6(3), N(2)ÈC(13)ÈO(13)
118.5(3).
The X-ray structure of a typical example (1: M \ Pd,
R \ Me) is shown in Fig. 1. The molecule adopts the expected
square planar coordination at palladium with the six-
membered PdP N C ring being in the coordination plane
2
2
[maximum deviation from the PdP N CCl mean plane is
2
2
2
[0.12 A for N(2) with O(13) being 0.06 A from this mean
New J. Chem., 2000, 24, 69È71
This journal is ( The Royal Society of Chemistry and the Centre National de la Recherche ScientiÐque 2000
69

View Article Online
Fig. 2 The X-ray structure of 2. Selected bond lengths (A) and angles
(¡): Pt(1)ÈCl(1) 2.342(4), PtÈCl(2) 2.387(3), Pt(1)ÈP(1) 2.188(3), Pt(1)È
S(13) 2.256(4), P(1)ÈN(1) 1.739(10), N(1)ÈC(13) 1.34(2), C(13)ÈS(13)
1.737(13); Cl(1)ÈPt(1)ÈCl(2) 91.10(14), P(1)ÈPt(1)ÈS(13) 88.02(13),
Pt(1)ÈP(1)ÈN(1) 106.8(4), P(1)ÈN(1)ÈC(13) 118.7(8), N(1)ÈC(13)ÈS(13)
121.7(10).
bonds are e†ectively single bonds whilst C(13)ÈS(13) is slightly
longer [1.737(13) A] than a formal C2S double bond.
We also found that reaction of the urea-phosphines with
Fig. 3 The X-ray structure of 3: (a) the full molecule and (b) view
showing the core geometry. Selected bond lengths (A) and angles (¡)
(NB: the molecule has approximate molecular two-fold symmetry, the
numbers in square brackets allow comparison of the symmetry related
parameters): Pd(1)ÈN(2) 2.083(4) [2.059(4)], Pd(1)ÈP(1) 2.2043(14)
[2.1985(14)], Pd(1)ÈO(32) 2.092(3) [2.075(3)], Pd(1)ÈP(2) 2.2764(14)
[2.2600(14)], P(1)ÈN(1) 1.674(5) [1.676(5)], N(1)ÈC(13) 1.424(7)
[1.414(7)], C(13)ÈN(2) 1.323(7) [1.328(7)], C(13)ÈO(13) 1.235(6)
[1.240(6)], P(2)ÈO(2) 1.536(4) [1.539(3)]; P(1)ÈPd(1)ÈN(2) 81.81(13)
[81.90(13)], Pd(1)ÈP(1)ÈN(1) 102.6(2) [102.3(2)], P(1)ÈN(1)ÈC(13)
119.4(3) [119.2(3)], N(1)ÈC(13)ÈN(2) 114.6(5) [114.2(5)], C(13)ÈN(2)È
Pd(1) 121.6(4) [121.9(4)], Pd(1)ÈP(2)ÈO(2) 113.9(2) [112.8(2)], Pd(1)È
O(32)ÈP(32) 128.4(7) [134.8(2)].
Pd(OAc) results in a PÈN cleavage reaction together with
2
formation of
a
[Ph PO]~ ligand incorporated into
a
2
Pd P O heterocycle in 60È65% yield according to eqn. (4).
2 2
2
The X-ray structure of 3 reveals (Fig. 3) that the square
planar palladium centres are spiro centres in the tricyclic
Crystal data
system. The PdPN C rings are close to planar [maximum
deviations for the two rings are 0.01 A for N(2) and [0.05 A
for N(31)] with the C2O and NMe groups being e†ectively
Common to all determinations: Bruker SMART di†ractome-
ter, Mo radiation, minimum full hemisphere of data, T \ 296
2
a
K,
C
reÐnements
employed
SHELXTL.
1:
coplanar with the PdPN C rings. The internal nitrogen angles
H
Cl N OP Pd, M \ 633.7, monoclinic, P2 /c (no. 14),
2
27 26
2
2
2
1
in the PdPN C ring are close to trigonal whilst the angle at
a \ 9.9076(1), b \ 14.700(1), c \ 19.051(1) A, b \ 101.70(1)¡,
2
phosphorus is slightly reduced from a perfect tetrahedral
U \ 2717(1) A
Ž
3, o
1.549 g cm~3, Z \ 4, k(Mo-K ) 1.02
calcd
a
angle and the internal angles at C(13)/C(43) are intermediate
between trigonal and tetrahedral. It is noticeable that the CÈN
bond lengths are quite localised with C(13)ÈN(2) being sub-
stantially shorter than C(13)ÈN(1). There are very few exam-
ples of crystallographically characterised M P O rings
mm~1, 11 787 reÑections measured, 3866 independent with
I [ 2p(I) to yield R \ 0.0263 and wR \ 0.0576 for 317
2
parameters.
2 Æ DMSO Æ CHCl :
C
H
Cl N OPPtS ,
3
18 23
5
2
2
M \ 750.81, triclinic, P1, a \ 11.404(1), b \ 11.563(1),
c \ 11.927(1) A, a \ 69.23(1), b \ 71.929(1), c \ 74.871(1)¡,
2 2
2
[M \ any metal, less than 8 examples; M \ Pd, Pt, one
U \ 1378(1) A
Ž
3, o
1.810 g cm~3, Z \ 2, k(Mo-K ) 5.80
calcd
a
example for each metal). In 3 the central Pd P O ring adopts
mm~1, 5986 reÑections measured, 3829 independent with
2 2
2
a cyclohexane chair-type geometry with the central P O core
I [ 2p(I) to yield R \ 0.0503 and wR \ 0.1149 for 272
2
2
2
having two PdOP planes inclined by ca. 138¡. Within this ring
parameters.
3 Æ H O Æ 2CH Cl :
C
H
Cl N O P Pd ,
2
2
2
56 58
4
4
5 4
2
the PÈO bond lengths [P(2)ÈO(2) 1.536(4) and 1.539(3) A] are
M \ 1345.5, triclinic, P1, a \ 11.695(1), b \ 15.487(1),
appropriate for a coordinated [Ph PO]~ anion and similar to
c \ 18.541(1) A, a \ 76.184(1), b \ 71.834(1), c \ 72.806(1)¡,
2
those reported for a Pd P O ring,10 but slightly shorter than
U \ 3008(1) A
Ž
3, o
1.486 g cm~3, Z \ 2, k(Mo-K ) 0.93
2 2
2
calcd
a
those reported for (Ph P)Pt(Ph PO) Pt(PPh ).11 The
mm~1, 14 316 reÑections measured, 8512 with I [ 2p(I) to
3
2
2
3
PdÉ É ÉPd distance in 3 is 4.442 A, which is considerably longer
than that found previously [3.32 A] and may suggest that the
complex reported10 by Matt et al. is a PdI system.
yield R \ 0.0430 and wR \ 0.113 for 668 parameters. In all
2
structures all of the non-H atoms were reÐned anisotropically
and the solvents were included in the reÐnements. H-atoms
were usually located from di†erence maps (or at least the
leading proton on methyl groups) and reÐned in idealised
geometries.
Experimental
All new complexes gave satisfactory microanalyses and the
expected parent ions in their mass spectra. Formation of 1–3
was under essentially identical conditions, i.e., reaction at
room temperature in CH Cl . Selected spectroscopic data:
CCDC reference number 440/158. See http://www.rsc.org/
suppdata/nj/a9/a908153d/ for crystallographic Ðles in .cif
format.
2
2
[Ph PN(Me)] CO
d
54.6, [Ph PN(Et)] CO
d
56.1,
2
2
P
2
2
P
References
[Ph PN(Me)] CS d 63.3, [Ph PN(Et)] CS d 67.8. 1: d 76.2,
2
P
2
P
2
2
P
P
2: d 78.31, 1JM31P-195PtN 3968 Hz, 3: d (CDCl ) 84.4 and
1
P. Bhattacharyya, A. M. Z. Slawin, M. B. Smith and J. D. Wool-
lins, Inorg. Chem., 1996, 35, 3675.
P
3
71.2.
70
New J. Chem., 2000, 24, 69È71

View Article Online
2
P. Bhattacharyya, A. M. Z. Slawin, D. J. Williams and J. D.
Woollins, J. Chem. Soc., Dalton T rans., 1995, , 3189.
R. Vogt and R. Schmutzler, Z. Naturforsch., T eil B, 1989, 44, 690.
M. Gruber and R. Schmutzler, Phosphus, Sulfur Silicon, 1993, 80,
181.
8
9
N. Burford, S. Mason, R. E. Spence, J. M. Whalen, J. F. Richard-
son and R. Rogers, Organometallics, 1992, 11, 2241.
3
4
S. Okaya, H. Shimomura and Y. Kushi, Chem. L ett., 1992, , 2019.
10 D. Matt, F. Ingold, F. Balegroune and D. Grandjean, J.
Organomet. Chem., 1990, 349, 399.
5
6
7
M. Gruber, P. G. Jones and R. Schmutzler, Phosphus, Sulfur
11 N. W. Alcock, P. Bergamini, T. M. Gomes-Carniero, R. D.
Jackson, J. Nicholls, A. G. Orpen, P. G. Pringle, S. Sostero and
O. Traverso, J. Chem. Soc., Chem. Commun., 1990, 980.
Silicon, 1993, 80, 195.
M. Gruber, R. Schmutzler and D. Schomburg, Phosphus, Sulfur
Silicon, 1993, 80, 205.
M. Gruber and R. Schmutzler, Phosphus, Sulfur Silicon, 1993, 80,
219.
L etter a908153d
New J. Chem., 2000, 24, 69È71
71