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Monohapto versus Dihapto CO2 Coordination in Bis(amine)Ni0 Complexes A CAS-SCF Study.

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force alignment along the (001) axis. NMR studies aimed at
polymer chain-length determination are presently being carried out.
Continuing research on intrazeolite polypyrrole and other
conducting polymers addresses issues such as the effect of
different host pore sizes and topologies on the polymer chain
length and transport properties of the resulting low-dimensional systems.
Received: July 14, 1989 [ Z 3443 IE]
German version: Angew. Chem. I01 (1989) 1737
111 M. Aldissi (Ed.): Proc. Inr. Conf Sci. Techno/. Synrh. Met. (ICSM 1988);
Synth. M e t . 28 (1989) No. 1-3; ibid. 29 (1989) No. 1.
[2] T. A. Skotheim (Ed.): Handbook of Conducting Polymers, Vol. I, Marcel
Dekker, New York 1986.
[3] L. Alcacer (Ed.): Conducting Polymers. Speriut Applications, Reidel,
Dordrecht 1987.
[4] J. B. Parise, J. E. MacDougall, N. Herron, R. D. Farlee, A. W. Sleight, Y.
Wang, T. Bein, K. Moller, L. M. Moroney, Inorg. Chem. 27 (1988) 221.
[5] N. Herron, Y. Wang, M.M. Eddy, G. D. Stucky, D. E. Cox, K. Moller, T.
Bein, 1 Am. Chem. SOC.I l l (1989) 530.
[6] K. Moiler, M. M. Eddy, G. D. Stucky, N. Herron, T. Bein, J. Am. Chem.
SOC.I l l (1989) 2564.
[7] J. J. Hopfield, J. N. Onuchic, B. N. Beratan, Science (Washington D C ) 241
(1988) 817.
[8] E L. Carter (Ed.): Molecular Electronic Devices I , ZI, Marcel Dekker, New
York 1982 and 1987.
191 D. W. Breck: Zeolite Molecular Sieves. R. E. Krieger Publishing Co.,
Malabar, FL, 1984.
[lo] a) Polypyrrole monolayer-type films have been intercalated between the
layers of FeOCl and V,O,. b) M. G. Kanatzidis, L. M. Tonge, T. J. Marks,
H. 0. Marcy, C. R. Kannewurf, J. Am. Chem. SOC.109 (1987) 3797;
c)M. G. Kanatzidis, C.-G. Wu, H. 0. Marcy, C. R. Kannewurf, J. Am.
Chem. SOC.f l l (1989) 4139.
1111 Polypyrrole fibrils with diameters between cd. 0.03 and 1 jim at 10-pm
length have been synthesized in Nuclepore membranes: a) R. M. Penner,
C. R. Martin, J. Electrochem. SOC.133 (1986) 2206; b) 2 . Cai, C. R. Martin, J. Am. Chem. SOC.111 (1989) 4138.
[12] In situ polymerization of pyrrole in the 0.68-nm diameter channels of
[(Me,Sn),Fe"'(CN),], has recently been reported: P. Brandt, R. D.
Rscher, E. S. Martinez, R. Diaz Calleja, Angew. Chem. 101 (1989) 1275;
Angew. Chem. Int. Ed. Engl. 28 (1989) 1265.
[13] Cur' forms of zeolite Y (LZ-Y 52; Alfa), mordenite (M; LZ-M5; Union
Carbide), and zeolite A (Alfa 5A) were obtained by ion exchange with
0.1 M Cu(NO,), solution and dehydration at 620 K
tom, resulting in
Cu,,Na,,Y, Cu, ,Na,M, and Cu,Na,,A (15, 2.5, and 8 Cu per unit cell,
respectively).The dry zeolites were equilibrated with pyrrole vapor (1 torr)
for 1 h at 295 K and then placed under vacuum for 1 h. Loadings were
determined gravimetrically. Polymerization of pyrrole was also observed
in FellLzeolite forms and when the monomer was introduced from solvents
such as water, toluene, or hexane.
[14] a) Prepared by chemical oxidation of pyrrole with FeCI, in water; b) R. E.
Myers, J. Electron. Muter. IS (1986) 61; c)S. P. Ames, Synth. M e t . 20
(1987) 365; d) S. Rapi, V. Bocchi, G. P. Gardini, ibid. 24 (1988) 217.
[15] a) K. G. Neoh, T. C. Tan, E. T. Kang, Polymer 29 (1988) 553; b) M. Zagorska, A. Pron, S. Lefrant, 2. Kucharski, J. Suwalski, P. Bernier, Synth.
Met. 18 (1987) 43.
[16] Similar observations were noted in the polypyrrole/FeOCI system: M. G.
Kanatzidis, personal communication; see also [lo].
1171 Obtained by excitation with an Ar ion laser at 457.9 nm, 5 mW.
(181 C. H. OIk, C. P. Beetz, Jr.; J. Heremans, J. Muter. Res. 3 (1988) 984.
(191 The estimated surface capacity for I-Mm crystals is 0.2 (Y) and 0.05 (M)
pyrrole per unit cell based on a 0.6-nm diameter for pyrrole.
1201 Pyrolysis mass spectra (up to 560 K) of all samples showed only desorption
of some excess monomer but no indication of short-chain oligomeric products.
[21] J. H. Kaufman, N. Coianeri, J. C. Scott, K. K. Kanazawa, G. B. Street,
Mol. Cryst. Liq. Crysr. 118 (1985) 171.
[22] On average, ca. 0.001 Curie-type spins per adsorbed monomer were observed.
[23] J. C. Scott, P. Pfluger, M. T. Krounbi, G. B. Street, Phys. Rev. B28 (1983)
2140.
1241 a) Carried out at 295 K with pressed wafers of the bulk polymers and of
zeolite powders by use of the four-point technique; b) F. M. Smits, Bell
Syst. Tech. J. 37 (1958) 711.
1694
0 VCH
VerIagsgesetlscJzafimbH, D-6940 Wernheim, 1989
Monohapto versus Dihapto CO, Coordination in
Bis(amine)Nio Complexes: A CAS-SCF Study
By Alain Dedieu* and Florent Ingold
[NiL,(CO,)] complexes (L = phosphane, amine) are
known to play a key role in many processes of organometallic chemistry.['] For instance, they may be critical
intermediates in various coupling reactions of CO, with
alkenes, alkynes, aldehydes, imines, or even oxygen at Nio
centers.['e-g.21They also display an interesting fluxional
behavior: 31PNMR spectra of a bisphosphane CO, complex
of nickel, both in s o l ~ t i o n and
[ ~ ~ in liquid C0,,[41 show a
single resonance. This has been attributed to an q' coordination of CO, at the carbon atom (A) or to a fast dynamic
process averaging the two qz coordination modes (e.g., B)
either through the q '-C coordination mode or through a fast
rotation around the Ni-(q2-C0,) b0nd.1~1We report here
the result of ab initio CAS-SCF calculations (CAS = complete active space), which indicate that another structure,
characterized by an q' coordination mode at the oxygen
atom (C) and by a strong diradical character, is close in
energy to the q2-C0, structure B, thereby providing a new
perspective on the reactivity pattern of this class of complexes.
A
B
C
Preliminary SCF calculations were first carried out with
the ASTERIX system of programs,'6' using a split valencetype basis set"] and geometries assumed from related X-ray
crystal structures or previous calculations on similar sysCAS-SCF calculations['8. 191 were then performed
using the same geometries and basis set. Such multiconfiguration SCF-type calculations are necessary to include nondynamical correlation effects and to give a balanced description of the bond-forming and bond-breaking processes.1211
In particular, they provide an appropriate way (1) to take
into account the manifold of low-lying electronic configurations, which is usually characteristic of nickel systems with a
low coordination number,'221and (2) to treat the diradical
and closed-shell species with a similar degree of accuracy.
They are also a convenient starting point for the study of
dynamical correlation effects (currently under way). Including these effects (and also adding polarization functions) will
probably improve the overall accuracy of the calculation but
should not alter the main conclusions obtained at the present
level of
The first salient result of the CAS-SCF calculations is the
fact that the q l - 0 structure C is found to be only
1.3 kcal mol-' higher in energy than the q2-C0, groundstate structure B.[231A complete optimization of the two
geometries might, of course, change this value somewhat,
but not to a great extent. Both structures are therefore close
to each other in energy, a result that was not expected on the
basis of the preliminary SCF calculations.[241The q'-C
structure A is computed to be much higher in energy (by
[I'
Dr. A. Dedieu, F. lngold
Laboratoire de Chimie Quantique, UPR 139 du CNRS
Universitt Louis Pasteur
4, rue Blaise Pascal, F-67000 Strasbourg (France)
0570-0833i89j1212-1694 $02.50/0
Angew. Chem. Int. Ed. Engt. 28 (1989) No. 12
46.8 kcal mol-' at the CAS-SCF
In addition, a
natural orbital analysis of the corresponding CAS-SCF wave
functions points to a strong diradical character for the ql-0
structure C. The orbital occupations of the the bonding
orbital between d+,, and n,& (the HOMO in the SCF
ground-state wave function) and its antibonding counterpart
Since these
(the LUMO) are 1.288 and 0.714, respectively.1251
two orbitals are equally spread over the metal and the CO,
ligand, the q '-0 structure C is probably best regarded as a
1,3 diradical centered on the nickel and carbon atoms. Most
probably C has a singlet ground state, since the triplet state
was computed to lie 4.1 kcal mol-' above the singlet state.
These results suggest that the coupling reaction of CO,
and C,H,, which has been observed experimentally at a Nio
center, rzbI might well involve a coordinated CO, attacked by
the incoming olefin rather than an electrophilic attack on a
coordinated C,H, by the carbon dioxide. In both cases the
attacked ligand has to slip in one way or another from an q 2
to an q ' coordination mode.1261But the q geometry for the
corresponding ethylene complex [Ni(NH,),(C,H,)]
is
found to be 29.0 kcal mol-' above the qZ-C,H, groundstate structure; hence, deformation of the qzgeometry to the
q' geometry is much less easy than deformation of the q2CO, structure B to the q'-CO, structure C. This is reflected
in the results obtained from CAS-SCF calculations performed for two geometries corresponding either to a 3-A
approach of C,H, to the nickel atom of [Ni(NH,),(q '-CO,)]
or to a 3-A approach of CO, to the nickel atom of
[Ni(NH,),(q 1-C2H4)].[271
The energy needed to reach the
first geometry from the separated reactants, [Ni(NH,),(q2CO,)] and C,H,, amounts to 14.9 kcal mol-', whereas the
energy needed to reach the second geometry from the separated reactants, [Ni(NH3),(q2-C,H4)] and CO,, amounts to
36.1 kcal mol- I . All these features are therefore consistent
with C,H, attack as the favored pathway. Work is now in
progress to investigate in more detail these two reaction
pathways and the influence of the ligand coordination pattern.
Received: July 10, 1989 [Z 3427 IE]
German version: Angew. Chem. 101 (1989) 1711
[l] Reviews; a) D. J. Darensbourg, R. A. Kudaroski, Adv. Organomet. Chem.
22 (1983) 129; b) D.A. Palmer, R. Van Eldik, Chem. Rev. 83 (1983) 51;
c) R. Ziessel, N0uv.J. Chim. 7(1983)613;d) D. J.Darensbourg,C.Ovalles,
CHEMTECH 1985 636; e) D.Walther, Coord. Chem. Rev. 79 (1987) 135;
f ) A . Behr, Angew. Chem. lOO(1988) 681; Angew. Chem. Int. Ed. Engl. 27
(1988) 661 ;g) P. Braunstein, D. Matt, D. Nobel, Chem. Rev. 88 (1988) 747.
[2] a) H. Hoberg, Y. Peres, C . Kruger, Y.-H. Tsay, Angew. Chem. Y9 (1987)
799; Angew. Chem. Int. Ed. Engl. 26 (1987) 771 ; b) H. Hoberg, Y Peres, A.
Milchereit, S. Gross, J. Organomet. Chem. 345 (1988) C17.
[3] M.Aresta, E. Quaranta, I. Tommasi, J. Chem. Soc. Chem. Commun 1988,
[lo] R. Raffenetti, R. D. Bardo, K. Ruedenberg in D. W. Smith. W. B. McRae
(Eds.): Energy Strucrure und Reactivity, Wiley. New York 1973, p. 164.
[ l l ] S. Huzinaga: Approximure Atomic Functions, Technzcai Report, University
of Alberta, Edmonton 1971.
[12] S. Huzinaga, J. Chem. fhys. 42 (1965) 1293.
[13] Structural parameters: a)Dihapto complex B: The geometry of the
CO, moiety was taken from the experimentally determined structure of
[Ni(P(~yclo-C,H,,)~}~(q~-C0,)I
[14]; the Ni-N bond was sel at 2.15 8, as
in the previous SCF study of Sakuki et al. [15] and the N-Ni-N angle at
90" (161. b ) q ' - 0 structure C:The geometry of the Ni(NH,), unit was
retained as in B, and the geometry of the Ni-CO, unit set as follows:
Nib0 = 1.868 A. C-0= 1.297 and 1.230 8, for the bound and nonbound
C-0 bonds, respectively; 0-C-0 angle = 130.3". These values are
taken from the X-ray crystal structure of the metallalactone complex
[Ni(dbu),(C,O,H,)] (dbu = 1.8-diazabicyclo[5.4.O]undec-7-ene) [2a] and
from an SCF optimization of the 0-C-0 angle. c) ql-C structure A:
The geometry of the Ni(NH,), unit was again retained as in B, and the
geometry of the Ni-CO, unit was set according to the previous SCF calculation of Sakakiet al. [15]. For the NH, ligand the experimental geometry [17]was chosen.
[14] M.Aresta, C.F. Nobile, V. G. Albano, E. Forni, M. Manassero, J. Chem.
SOC.Chem. Commun 1975,636.
I151 S. Sakaki, K. Kitaura, K. Morokuma, Inorg. Chem. 21 (1982) 760.
[16] CAS-SCF calculations carried out for an N-Ni-N angle of 1 2 0 in B
showed that the energy was lowered by only 0.4 kcal mol-I.
[17] Tables of Interatomic Dbtances (Spec. fubl. Chem. Soc. 1R (1965)).
[18] a) B. 0.Roos,P. R.Taylor, P. E. M. Siegbahn, Chem. fhys. 48(1980) 157;
b) P. E. M. Siegbahn, J. Almlof, A. Heiberg, B. 0.Roos, J. Chrm. Ph.w 74
(1981) 2384; C) B. 0.Roos, fqt. J. Quantum Chem. Symp. 14 (1980) 175.
[19] The active space of the CAS-SCF calculations was made of six active
orbitals populated by eight electrons for the [Ni(NH,),(CO,)] system.
~~ ~x&,)
, . account for the
These active orbitals (d,,, d,, y i r 4s, x ~n I ~( ~ and
main bonding interactions as well as for the sd hybridization features. For
the [Ni(NH,),(CO,)] + C,H, system, the J C and
~ I(&.~
~orbitals
~
were
added, giving rise to a set of eight active orbitals populated by ten electrons. The frozen core approximation 1201was used throughout the calculations in order to avoid error effects due to basis-set superposition.
I201 L.Pettersson, U. Wahlgren, Chem. Phys. 69 (1982) 185.
[21] See, for instance. a) 1. E. Backvall, E. E. Bjorkman, L. Pettersson, P. Siegbahn,A. Strich,J. Am. Chem. SOC.107(1985) 7408; b) M. R. A. Blomberg,
P. E. M. Siegbahn, 3. E. Backvall, ibid. 109 (1987) 4450.
[22] See, for instance, a) M. R. A. Blomberg, U. B. Brandemark, P. E. M. Siegbahn, K. B. Mathisen, G. Karlstrom, J. fhys. Chem. R9 (1985) 2171;
b) P. 0.Widmark, B. 0. Roos, P. E. M. Siegbdhn, ibid. 89 (1985) 2180.
1231 The total CAS-SCF energies are: B, -1803.7096; C, -1803.7075; A,
-1803.6351 Hartree (1 Hartree = 627.7 kcal mol- ').
[24] The total SCF energies are: B, -1803,6196; C, -1803,5774; A,
- 1803.5190 Hartree.
1251 This corresponds to an important weight (35%) (in the C1 expansion) of
the configuration obtained through a double excitation from the HOMO
to the LUMO with respect to the ground-state SCF configuration (whose
weight in the CI expansion amounts to only 63%).
[26] The geometry of the metallactone ring corresponds either to an q'-CO, or
to an q1-CZH,unit. Moreover, the slippage of the ethylene ligand from the
dihapto coordination mode to the monohapto coordination mode polarizes the C,H, x orbital on the uncoordinated carbon atom, making i t more
prone to an electrophilic attack by CO,.
[27] This corresponds to a C-C distance of about 2.5 p\. SCF calculations,
which were also carried out for an approach of 2.5 A (corresponding to a
C-C distance of about 2 A), yielded total energies which were already
lower than the energies of the separated reactants.
450.
[4] M. G. Mason, J. A. Ibers, J. Am. Chem. Soc. 104 (1982) 5153.
[5] M. Aresta, E. Quaranta, I. Tommasi, R. Gobetto, NATO-AS1 Summer
School o n Enzymatic and Model Carboxylation and Reduction Reactions
(Ginosa. Italy, 1989).
161 M. Benard, A. Dedieu, J. Demuynck, M.-M. Rohmer, A. Strich, A. Veillard, R. Wiest, Asterix. a system of programs for the IBM 3090, unpublished.
[7] Basis sets: (14,9,6) contracted to <6,4,3> for the nickel atom [8, 91; (9,s)
contracted to <3,2> for the first-row atoms Ill]; and (4) contracted to
< 2 > for the hydrogen atoms[12].
[8] I. Hyla-Kryspin, J. Demuynck, A. Strich, M. Benard, J. Chem. Phys. 75
(1981) 3954.
[9] The original (13,7,5) basis set [8]is modified by the addition of an s primitive of exponent 0.37458 to suppress the gap between the functions needed
to describe the widely separated 3 s and 4s shells and two p functions of
exponents 0.30117 and 0.09739 to describe the 4 p shell, and by replacing
in the d shell the last function by two functions of exponents 0.40354 and
0.13013. These exponents were chosen according to the even-tempered
criterion [ l o ] .
Angew. Chem. Int. Ed. Engl. 28 (1989) No. 12
Phosphaalkenes from Monochlorophosphanes
and Alkylidenetriphenylphosphoranes
By Gottfried Markl* and Walter Bauer
The recently published synthesis by E: Mathey et al.['] of
complex-stabilized phosphaalkenes 2 by carbonyl olefination with the phosphorylphosphide complexes 1 leads us to
describe a new general synthesis of phosphaalkenes 10 involving the reaction of alkylidenetriphenylphosphoranes 3
with chloro-(2,4,6-tri-tert-butylphenyl)phosphane 6.
[*] Prof. Dr. G. MPrkl, DipLChem. W. Bauer
Institut fur Organische Chemie der Universitit
Universitiitsstrasse 31, D-8400 Regensburg (FRG)
0 VCH Pkriagsgeseilschafz mhH. D-6940 Weinheim, 1989
0570-0833j89jl212-1695 $02.SOj0
1695
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dihapto, monohapto, coordination, stud, amin, cas, co2, versus, bis, complexes, scf, ni0
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