Bifunctional Carriers of Organometallic Functionalities: Alkali-Metal

Raffaella Crescenzi, Euro Solari, Carlo Floriani, Angiola Chiesi-Villa, and Corrado Rizzoli. Journal of the American Chemical Society 1999 121 (8), 16...
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Organometallics 1995,14, 4816-4824

4816

Bifunctional Carriers of Organometallic Functionalities: Alkali-Metal-Zirconium-Hydrido, -Alkyl, and -Allyl Derivatives of mso-Octaethylporphyrinogenand Their Reaction with Isocyanides Denis Jacoby, Sylviane Isoz, and Carlo Floriani" Institut de Chimie Midrale et Analytique, BCH, Uniuersitd de Lausanne, CH-1015 Lausanne, Switzerland

Kurt Schenk Institut de Physique, Universitt! de Lausanne, CH-1015 Lausanne, Switzerland

Angiola Chiesi-Villa and Corrado Rizzoli Dipartimento di Chimica, Universita di Parma, I-43100 Parma, Italy Received May 10, 1995@ The reaction of alkali-metal organometallics with the meso-octaethylporphyrinogenzirconium complex [(~5:~1:r5:~1-Et~N4)Zr(THF)I (l),acting as a bifunctional carrier, led to the formation of bimetallic K-Zr and Li-Zr organometallics. Such compounds formed from the addition of the nucleophilic fragment to zirconium, while the alkali-metal cation remained bonded to the electron-rich periphery of the porphyrinogen moiety. The addition of KH to 1 in a 1:l molar ratio led to the formation of the dinuclear complex [((r5:r1:r5:r1-Et~N4)Zr}z{pC-KH}21 (2), while with a large excess of KH under controlled conditions we obtained a tetranuclear polyhydride species, [{(r5:r1:r1:r1-EtsN4)Zr}4{KH}s~THF)1~l, (31,having the [Zr4&Hs] skeleton containing both pa- and p3-hydrides. In toluene-THF, the addition of LiR to 1 gave the monomeric dimetallic lithium-zirconium alkyls [{(y5:y1:r1:r1-EtgN4)ZrR}{Li(THF)2}1 (R = Me, 4; R = But, 5). The reaction of 1 with potassium allyl gave a structurally complex, bimetallic, polynuclear compound where the allyl fragment interacts in both an r1 and r2fashion, with zirconium and potassium, respectively, to give complex 6, [(r5:r1:r1:r1-Et8N4)Zr01-r3_C3H5)Kln.Other potassium-zirconium alkyl derivatives are accessible via: (i) the hydrozirconation of olefins using complex 2 (the reaction of 2 with ethylene (7)) and (ii) the exchange of the alkali-metal gave [{(~5:l;11:~1:r1-EtsN4)Zr-CH~CH3}~~-K)~l cation (the reaction of 4 with KH led to the corresponding KMe derivative supported by 1, [{(~5:r1:~1:~1-EtsN4)Zr-Me}{K(THF)}~l (8)). The bimetallic K-Zr alkyl and hydrido derivatives are very reactive in insertion reactions. The reaction of 2 and 4 with ButNC led respectively, to the corresponding r2-iminoformyl [{(r5:rl1:r1:r1-EteNq)Z~r2-CH=NBut))2K)21 (9)), and q2-iminoacetyl ([{(y5:y1:~1:~1-Et~N4)Zr(~z-C(Me)=NB~t)}{ Li(THF)}](lo)),complexes. As such, 0 and 10 should be considered as polar alkali-metal iminoformyl and iminoacetyl derivatives bonded to the bifunctional complex 1.

Introduction Th.e Zr-H and Zr-C functionalities have played a primary role in the development of organometallic PLbstract published in Advance ACS Abstracts, September 1,1995. (1) (a) Wailes, P. C.; Courts, R. P.; Weigold, H. Organometallic Chemistry of Titanium, Zirconium and Hafnium; Academic: New York, 1974.(b) Cardin, D.J.; Lappert, M. F.; Raston, C. L. Chemistry of Orga nozirconium and Hafnium Compounds; Wiley: New York, 1986. (c) Buchwald, S. L.; Nielsen, R. B. Chem. Rev. 1988,88, 1047. (d) Negishi, E.-I. In Comprehensive Organic Synthesis; Paquette, L. A., Ed.; Pergamon: Oxford, U.K., 1991;Vol. 5, p 1163.(e) Grossman, R. B.; 13uchwald, S. L. J. Org. Chem. 1992, 57, 5803 and references therein. (0 Negishi, E.-I.;Takahashi, T.Acc. Chem. Res. 1994,27,124 and references therein. (g) Schore, N. E. In Comprehensive Organic Synr!hesis;Paquette, L. A., Ed.; Pergamon: Oxford, U.K., 1991;Vol. 5, p 10137.(h) Erker, G.; Kriiger, C.; Muller, G. Adv. Organomet. Chem. 19815,24, 1 and references therein. (i) Swanson, D. R.; Negishi, E. Orgmometallics 1991,10, 825. (j) Erker, G.; Pfaff, R.; Kriiger, C.; Weiner, S. Organometallics 1993, 12, 3559. (k) Erker, G.;Noe, R.; Kruger, C.; Werner, S. Organometallics 1992,11,4174.(1) Erker, G.; PfalT, R. Organometallics 1993, 12, 1921. (m) Jordan, R. F. Adv. Organomet. Chem. 1991,32,325. @

chemistry and in the application of organometallic methodologies to organic synthesis and catalysis.l In addition, an equally important role has been played by the alkali-metal organometallics.2 We introduced recently the use of meso-octaalkylporphyrinogencomplexes as carriers for polar ~rganometallicb,~ t o combine the advantages of both approaches and eventually to move t o the use of such complexes as catalysts. The carrier properties of polar organometallics have been largely developed only in case of the W mmetalate which include the widely used cuprate deriva~

~~

(2)(a) Schlosser, M. Organoalkali Reagents In Organometallics in Synthesis; Schlosser, M . , Ed.; Wiley: New York, 1994;Chapter 1. (b) As a general reference to organoalkali-metal complexes: Weiss, E. Angew. Chem., Int. Ed. Engl. 1993,32,1501. (3)(a) Jacoby, D.;Isoz, S.; Floriani, C.; Chiesi-Villa, A.; Rizzoli, C. J. Am. Chem. Soc. 1996,117,2805 and references therein. (b) Ibid. 1996,I 1 7, 2793 and references therein. (c) Jacoby, D.; Floriani, C.; Chiesi-Villa, A.; Rizzoli, C. J. Am. Chem. SOC. 1993,115, 3595 and

references therein.

0276-733319512314-4816$09.00/00 1995 American Chemical Society

Bifunctional Carriers of Organometallics

Organometallics, Vol. 14, No. 10,1995 4817

Scheme 1

of which is reported here. The use of a 2:l MH:Zr ratio under rigorous reaction conditions (see Experimental Section) led to the formation of the polynuclear species 3. An excess of KH and drastic reaction conditions led, instead, to the mono- and bis-metalation of the mesoethyl Et THF not shown In the case of 2, each zirconium atom is q5:q1:q5:q1bonded to the porphyrinogen anion, while each potassium cation is $-bonded to two pyrrolyl anions t o form a bent bis(cyclopentadieny1)-type sandwiche6In the case J of 3, due to the complexity of the structure we show only the potassium-zirconium-hydride skeleton, using the same numbering scheme shown in Figure 1A. The structure consists of the centrosymmetric tetramer K4ZrdHa.? Only four K ions participate in the metalhydride skeleton, while the other four are bonded to the porphyrinogen periphery (Kl, Kl’, K3, K3’). In the asymmetric unit, we have two independent zirconium ions, Zrl and Zr2, each one being q1:q1:q1:q5-bondedto the porphyrinogen. Selected interatomic distances are listed in Table 1,while conformational parameters are shown in Table 2. The coordination environments for Et the four independent K ions are shown in Figure 1B. K1, K2, and K3 show a bent-sandwich type of bonding [(t15-?1-t15-?1-EtaN4)Zr(~-Kn)l~ [ ( ( ~ ~ 1 - ~ ~ - ~ 1 - E t ~ N ~ ) Z r ) ~ ( K H ) ~ ~ ( T H to F ) i two ol pyrrolyl anions with a dihedral angle between 2 3 the ring planes varying from 78.9(2) to 55.4(2) to 34.4(3)”,respectively, around the metal ion. The K-q5t i ~ e s .We ~ report here a number of examples of polar pyrrolyl anion centroid distances range from 2.928(7) organometallics,especially for potassium, carried by the to 3.233(3) A, the longest one being observed for K1. We zirconium-meso-octaethylporphyrinogen3c complex. should emphasize that the K-C distances for this case These potassium derivatives can add as such or can be fall in a rather wide range (-0.5 A). Nevertheless, the formed directly on the carrier via a hydrozirconation geometry of these interactions, the relevant deformareaction or metathesis from another alkali-metal detions they exert on the conformation of the [Zr(EtsNdI rivative. The latter approach has made available some moieties, and their continuous variations suggest q5nearly inaccessible potassium-organometallic derivapyrrole-alkali-metal interactions. In a single case, we tives2 by a very smooth route. The reactions of the observe one pyrrolyl anion q5-bonded to two potassium Zr-H and Zr-C bonds with ButNC leading to q2cations (K3, K4‘) on both faces (Figure 1A). In the iminoformyl and q2-iminoacylgroups are reported. structure there are two kinds of hydrides: the doubly bridging H10 and H20 and the triply bridging H30 and Results and Discussion H40, with the Zr-H and K-H distances being significantly shorter for the p2 than for the p3 mode (Table The bifunctional nature of complex 1 allows its use 1h8 We were unable to identify the bridging hydrido for carrying polar, ion-pair, and ionic species. The metal ligands in the NMR spectrum. The only structural site behaves as a Lewis acid center, while the electroninformation we can draw from the NMR spectrum is rich periphery, i.e. the a-bonded pyrrolyl anions, is the q1:q1:q1:q5bonding mode of the porphyrinogen available for binding metal ions. This behavior of 1 is around the zirconium ions in solution, as we found for exemplified bp its reactivity with MH [M = Li, Na, Kl, the structure in the solid state. which is particularly complex, and depends on (i) the Equation 1 shows an interesting extension of the use nature of the alkali-metal ion, (ii) the reaction condiof 1 t o bind polar organometallics. The reactions shown tions, and (iii) the MH:Zr stoichiometric ratio. In in (1) were carried out in a mixture of toluene and THF general, such a reaction leads either to a 1:l dimeric and complexes 4 and 5 were obtained as light yellow adduct (see 2)3c96or to the metalation of the meso-ethyl crystalline solids upon addition of n-hexane. groups.3a We report here the full details of the reaction The structure displayed for 4 and 5 is based on the of 1 with KH, leading to an unprecedented polynuclear X-ray analysis results obtained for 5 (vide infra). The hydride. The reaction of 1 with KH in a 1:l KH:Zr ratio led to the dinuclear complex 2, the detailed synthesis (7) (a) For a survey of group IV and V hydrides, see: Toogood, G. (4) (a) Reetz, M. T.In Organotitanium Reagents in Organic Synthesis; Springer: Berlin, Germany, 1986. (b) Reetz, M.T.; Steinbach, R.; Westermann, J.; Peter, R.; Wenderoth, B. Chem. Ber. 1986, 118, 1441. (c) Reetz, M. T.;Wenderoth, B. Tetrahedron Lett. 1982,23, 5259. (d) Morris, R. J.; Girolami, G. S. Organometallics 1991, 10,792. (e) Quan, R. W.; Bazan, G. C.; Kiely, A. F.; Schaefer, W. P.; Bercaw, J. E. J . Am. Chem. SOC.1994,116,4489. (5) (a) Lipshutz, B. H.; Sengupta, S. in Organic Reactions; Paquette, L. A,, Ed.; Wiley: New York, 1992; Vol. 41, Chapter 2. (b) Lipshutz, B. H. In Organometallics in Synthesis, a Manual; Schlosser, M., Ed.; Wiley: New York, 1994; Chapter 4. (6) Jacoby, D.; Floriani, C.; Chiesi-Villa,A.; Rizzoli, C. J.Am. Chem. SOC.1993,115, 7025.

E.; Wallbridge, M. G. H. Adv. Inorg. Chem. Radiochem. 1982,25,267. (b) Carlin, D.J.; Lappert, M. F.; Raston, C. L. Chemistry ofOrganoZirconium and -Hafnium Compounds; Ellis Honvood: Chichester, U.K.,1986. (c) Cardin, D. J.; Lappert, M. F.; Raston, C. L. In Comprehensive Organometallic Chemistry; Wilkinson, G., Stone, F. G. A., Abel, E. W., Eds.; Pergamon: Oxford, U.K., 1981; Vol. 3, Chapter 23.2, p 45. (d) Schwartz,J.Pure Appl. Chem. 1980,52,733.Wolczanski, P. T.;Bercaw, J. E. ACC.Chem. Res. 1980, 13, 121. (e) Labinger, J. A. Transition Metal Hydrides; Dedieu, A,, Ed.; VCH: Weinheim, Germany, 1992. Buchwald, S. L.; La Maire, S. J.; Nielsen, R. B.; Watson, B. T.;King, S. M. Tetrahedron Lett. 1987,28, 3895. (8) (a) Evans, W. J.; Meadows, H. J.; Hanusa, P. T. J . Am. Chem. SOC.1984, 106, 4454. (b) Wailes, P. C.; Weigold, H.; Bell, A. P. J. Organomet. Chem. 1972,43, C29.

4818 Organometallics, Vol. 14,No.10,1995

({(q5-ql-ql-ql-EtsNq)Zr-R)(Li(THF)2}] R=Me,4 R = Bun, 5

complexation of the polar LiR unit occurs with the separation of the ion pairs, with the nucleophilic alkyl group adding to zirconium, while the lithium cation is complexed by the porphyrinogen periphery. The bonding mode of the porphyrinogen, as discussed in detail in a previous report, changes from q5:q1:q5:~l to q5:q1: ql:ql as a consequence of a change in the electronic demands of the metal and, to some degree, for steric reason^.^^?^ A major question is whether such a bonding mode remains unchanged in solution, or what kind of relationship may exist between the structure in the solid state and that in solution. The lH NMR spectrum at room temperature is in agreement with two kinds of pyrroles, namely two v5 and two q1 types. When the (9)(a) Jacoby, D.;Floriani, C.; Chiesi-Villa,A.; Rizzoli, C. J. Chem. Soc., Chem. Commun. 1991,790.(b) Rosa, A.;Ricciardi, M.; Sgamellotti, A.; Floriani, C. J. Chem. SOC.,Dalton Trans. 1993,3759.

Jacoby et al.

temperature raised to 330 K, a singlet for the pyrrolic 3,4-protons was observed, apparently consistent with a fluxional behavior for the pyrrole fragments exchanging their position from v5 to q1 to q5. However, when the temperature was lowered, no change was observed in the NMR spectrum.. We observed two triplets for the methyl groups of the eight meso-ethyl groups, and a single quartet for the methylene^,^ indicating that the major geometrical differentiation occurs for the methyl group rather than for the methylene moiety. This is due to some rigid conformational effects of the ethyl groups, four of them protecting the metal and four outside of the metal coordination sphere.1° The structure of 5 is reported in Figure 2, and relevant bond distances and angles are listed in Table 3. The four nitrogen atoms lie in a plane from which Zr is displaced by 0.819(1) A toward the butyl ligand. The molecule maintains a saddle-shaped conformation, though small differences are observed in the dihedral angles (Table 2). The porphyrinogen ligand shows the v5:q1:q1:q1-bondingmode with the +bonded pyrrole ring nearly perpendicular to the Nq core. The [Li(THF)# cation is linked to N4 (2.109(7) A) and to C1 (albeit by a rather long distance, 2.642(10) A). The Zr-C(Bun) (10)De Angelis, S.;Solari, E.; Floriani, C.; Chiesi-Villa,A.; Rizzoli, C. J. Am. Chem. SOC.1994,116,5691,5702.Jacoby, D.;Floriani, C.; Chiesi-Villa,A.; Rizzoli, C. J. Chem. SOC.,Chem. Commun. 1991,220. Jubb, J.; Jacoby, D.; Floriani, C.; Chiesi-Villa, A.; Rizzoli, C. Znorg. Chem. 1992,31,1306.

Organometallics, Vol. 14, No. 10,1995 4819

Bifunctional Carriers of Organometallics

Table 1. Selected Bond Distances (A)and Angles (deg) for Complex 3” Zrl-N1 Zrl-N2 Zrl-N3 Zrl-N4 Zrl-C16 Zr 1-H10 Zr 1-H20 K2-Hl0 K1-01 K1-N1 K1-C1 K1-C2 K2-N2 K2-C6 K2-c7 K3-N7 K3-C51 K3-C52 K4-N6 K4-C46 K4-C47 N1-C1 N1-C4 N2-C6 N2-C9 C18-Zrl-Cl9 C17-Zrl-Cl8 C16-Zrl-C17 N4-Zrl-Cl9 N4-Zrl-C16 Cp4-Zrl-N3 01-K1-02 N5-K2-C44 N5-K2-C41 c43-K2-c44 0 5-K3 -N8 04-K3-N8 04-K3-05 N6-K4-C49 N6-K4-C46 C46-K4-C47

2.306(5) 2.286(4) 2.292(5) 2.384(4) 2.505(5) 1.78 1.79 2.51 2.724(6) 3.250(4) 3.471(6) 3.622(9) 3.438(4) 3.411(6) 3.221(6) 3.010(5) 3.314(7) 3.540(9) 3.458(6) 3.253(8) 3.135(8) 1.401(7) 1.399(7) 1.411(8) 1.366(8) 31.3(2) 31.8(2) 31.4(2) 32.0(2) 32.7(2) 95.3(2) 83.2(2) 25.6(1) 25.3(1) 25.1(2) 113.5(2) 164.5(2) 81.9(2) 23.7(1) 23.8(1) 25.0(2)

Zrl -C17 Zrl-C18 Zrl-C19 Zrl-Cp4

2.614(5) 2.601(5) 2.509(6) 2.231(5)

K2-H20 K2-H40

2.51 2.90

K1-02 Kl-C3 Kl-C4 K1-Cpl K2-C8 K2-c9 K2-cp2 K3-C53 K3-C54 K3-cp7 K4-C48 K4-C49 K4-Cp6 N3-Cll N3-Cl4 N4-Cl6 N4-Cl9

2.702(6) 3.531(8) 3.350(7) 3.233(3) 3.168(5) 3.304(6) 3.090(6) 3.428(7) 3.076(7) 3.063(7) 3.325(8) 3.531(7) 3.123(7) 1.352(6) 1.388(7) 1.380(8) 1.354(7)

Zr2-N5 Zr2-N6 Zr2-N7 Zr2-NS Zr2-C56 Zr2-H30 Zr2-H40 K4-H30 K1-N1 Kl-N3 K1-C11 K1-C12 K2-N5 K2-C41 K2-C42 K3-03 K3-04 K3-05 K4-N7’ K4 -C51’ K4-C52’ N5-C41 N5-C44 N6-C46 N6-C49

2.251(4) 2.246(4) 2.325(4) 2.408(5) 2.493(5) 1.80 2.08 2.66 3.261(4) 3.148(5) 3.317(7) 3.593(7) 3.171(5) 3.172(7) 3.153(8) 2.712(8) 2.716(4) 2.723(6) 3.020(5) 3.119(7) 3.358(8) 1.392(8) 1.400(8) 1.395(8) 1.435(7)

Zr2-C57 Zr2-C58 Zr2-C59 Zr2-Cp8

2.651(5) 2.603(5) 2.481(6) 2.235(6)

K4-H40 K4-H30’

2.79 2.90

K1-N4 Kl-Cl3 Kl-Cl4 K1-Cp3 K2-c43 K2-c44 K2-cp5 K3-N8

3.380(4) 3.598(8) 3.372(7) 3.201(7) 3.140(8) 3.147(6) 2.928(7) 3.011(4)

K4-C53’ K4- C54‘ K4-Cp7’ N7-C51 N7-C54 N8-C56 N8-C59

3.438(9) 3.201(8) 3.009(8) 1.367(7) 1.393(8) 1.353(10) 1.369(7)

Cp4-Zrl-N2 Cp4-Zrl-N1 N2-Zrl-N3 Nl-Zrl-N3 N1-Zrl-N2

162.3(2) 94.6(2) 77.4(1) 127.0(1) 77.7(1)

C58-Zr2-C59 C57-Zr2-C58 C56-Zr2-C57 N8-Zr2-C59 N8-Zr2-C56 Cp8-Zr2-N7

32.1(2) 31.1(2) 31.7(2) 32.5(2) 32.0(2) 94.5(2)

Cp8-Zr2-N6 Cp8-Zr2-N5 N6-Zr2-N7 N5-Zr2-N7 N5-Zr2-N6

162.5(2) 95.5(2) 81.5(2) 138.0(1) 76.9(2)

C42-K2-C43 C41-K2-C42

26.0(2) 25.0(2)

25.6(2) 24.9(2)

92.3(2) 92.1(2) 86.0(2) 25.2(2) 23.1(2)

23.8(1) 23.3(1) 23.8(2) 26.4(1) 24.2(1) 22.6(2) 25.7( 1) 25.7(1) 23.9(2)

C7-K2-C8 C8-K2-C9

03-K3-N8 03-K3-05 03-K3-04 C47-K4-C48 C48-K4-C49

N2-K2-C6 N2-K2-C9 C6-K2-C7 N7-K3-C54 N7-K3-C51 C51-K3-C52 N7’-K4-C51’ N7’-K4-C54’ C51’-K4-C52’

C52-K3-C53 C53-K3-C54

23.2(2) 23.7(2)

C52’-K4-C53’ C53’-K4-C54‘

23.8(2) 23.6(2)

a Cpl, Cp2, Cp3, Cp4, Cp5, Cp6, Cp7, and Cp8 refer to the centroids of the pyrrole rings containing N1, N2, N3, N4, N5, N6, N7, and N8 respectively. The prime denotes a transformation of -z, -y, 1 - z.

Table 2. Comparison of Structural Parameters for Compounds 3,5,6, and 10 dist of atoms from N4 core, A N1 N2 N3 N4 Zr dist of Zr from A, Ab dist of Zr from B, A dist of Zr from C, A dist of Zr from D, A dihedral angles between the N4 core and the A-D rings, deg A

B C D a

3a

5

6

1CP

-0.044(4) [-0.034(4)1 0.046(4) [ 0.064(5)1 -0.044(4) [-0.037(4)1 0.042(4) [0.052(5)1 0.977(1) [ 0.848(1)1 1.066(1) [0.457(1)1 1.511(1)[1.328(1)1 0.849(1) [0.023(1)1 2.214(1) [2.219(1)1

-0.004(2) 0.005(2) -0.004(2) 0.004(2) 0.819(1) 1.775(1) 0.806(1) 2.273(1)

-0.016(6) 0.012(5) -0.011(5) O.OlO(5) 0.864(1) 1.002(1) 1.735(1) 0.929(1) 2.215(1)

-0.095(2) 0.097(2) -0.084(2) 0.082(2) 0.910(1) 0.432(1) 1.145(1) 0.217(1) 2.261(1)

126.5(2) [166.8(2)1 163.0(2) [162.0(2)1 132.1(2) [151.6(2)1 90.1(2) [ 90.2(2)1

134.7(1) 147.9(1) 136.9(1) 92.1(1)

130.8(2) 152.3(2) 132.3(2) 92.1(2)

137.0(1) 158.3(1) 156.7(1) 94.8( 1)

0.880(1)

Molecule B in brackets. A-D refer to the pyrrole and pyridine rings containing N1, N2, N3, and N4, respectively.

bond distance is like that of the cyclopentadienyl derivatives. lb Equation 2 shows a further example of the use of 1 to bind polar organometallics. The reaction of 1 with potassium allyl gave 6 as a yellow crystalline solid. Its

lH NMR spectrum at 298 K is not informative on the allyl bonding mode, while it shows two singlets for the pyrrolic 3,4-protonsof the same intensity, indicating the presence of two q5- and two ql-pymolyl anions in solution. However, the solid-state structure, as shown

4820 Organometallics, Vol. 14,No. 10,1995

Jacoby et al.

C39A '

7'

Figure 2. SCHAKAL perspective view of complex 5. Table 3. Selected Bond Distances (A)and Angles (deg) for Complex 5" Zrl-N1 Zrl-N2 Zrl-N3 Zrl-N4 Zr 1-C 16 Zr 1-C 17 Zr 1-C 18 Zr 1-C 19 Zrl-Cp4 Zrl-C37 Lil-C1 Lil-01 Lil-02 Lil-N4 N1-C1 Nl-C4 N2-C6 C37-Zrl-Cp4 N3-Zrl-Cp4 N2-Zrl-Cp4 N2 -Zr 1-C37 N2-Zrl-N3 N1-Zrl- Cp4 Nl-Zrl-C37 Nl-Zrl-N3 Nl-Zrl-N2 Zrl-Nl-C4 Zrl-N1-C1

2.227(3) 2.203(2) 2.218(3) 2.435(2) 2.552(3) 2.682(3) 2.685(4) 2.553(4) 2.296(3) 2.248(3) 2.64200) 1.892(9) 1.969(8) 2.112(6) 1.396(4) 1.380(4) 1.386(5)

N2-C9 N3-Cll N3-Cl4 N4-Cl6 N4-Cl9 Cl-C2 C2-C3 c3-c4 C6-C7 C7-C8 C8-C9 Cll-c12 C12-Cl3 C13-Cl4 C16-Cl7 C17-Cl8 C18-Cl9

100.1(1) 95.3(1) 167.70) 92.2(1) 80.0(1) 95.1(1) 104.4(1) 136.4(1) 81.0(1) 127.4(2) 121.3(2)

a Cp4 refers to the N4,C 16,C17,C18,C19.

Cl-Nl-C4 Zrl-N2-C9 Zrl-N2-C6 C6-N2-C9 Zrl-N3-C14 Zrl-N3-C11 Cll-N3-C14 Zrl-N4-C19 Zrl-N4-C16 C16-N4-C19 Zrl-C37-C38

centroid

of the

1.402(4) 1.393(5) 1.390(4) 1.383(4) 1.393(5) 1.364(4) 1.406(5) 1.371(4) 1.380(5) 1.390(6) 1.375(5) 1.370(6) 1.402(5) 1.364(6) 1.388(5) 1.403(6) 1.391(4) 106.0(3) 110.9(2) 113.2(2) 106.3(3) 122.4(2) 126.8(2) 105.6(3) 78.5(2) 78.6(2) 105.8(3) 128.8(3) pyrrolic ring

toluene

in Figure 3, is significantly different from that observed in solution. Complex 6, which crystallizes with one THF

1

C37"

Zrl"

0

Figure 3. SCHAKAL perspective view of complex 6 showing the polymeric chain. Primes refer to the following transformations: ('> x, -y, 0.5 z; ("> x, y, 1 - z; ("7 x, -y, -0.5 Z.

+

+

molecule for every two complex molecules, has a polymeric chain structure running parallel to the crystallographic [OOl] axis (Figure 3), where the porphyrinogen units are bridged by potassium cations (Table 4). The porphyrinogen unit shows an ql:ql:ql:$ bonding mode to zirconium with a conformation close to that reported for 5 (see Table 2). The four nitrogen atoms lie in a plane which is nearly perpendicular to the $-bonded pyrrole. The potassium cation bridges two adjacent porphyrinogens related by a C glide. Potassium is q5bonded to the pyrrolyl anion containing N1 q3-bonded to that containing N3 and C11, +bonded to N2, and linked to an adjacent porphyrinogen unit via an q2interaction with the allyl group (C37 and C38) and a pyrrolyl anion (C7 and C8) (Figure 3). Although the disorder affecting C37 and C38 from the allyl group does not allow discussion of the C-C bond distances, the data in Table 4 support the a-bonding mode of the allyl to zirconium (Zr-C37,2.271(8) A;Zr-C38A, 3.22(2)A;ZrC38B, 3.31(3)A). C38 and C39 of the allylic group were found to be disordered over two positions (A and B). It is well-known that the alkali-metal ion plays a crucial role in the chemistry of polar organometallics.2 We expect that the same would be true for the case of these polar organometallics bonded to an appropriate carrier. We should admit that potassium organometallics are not as numerous and as easily available as the corresponding lithium derivatives.2 In order to overcome such difficulties, we have in our case two possibili-

Organometallics, Vol. 14,No. 10, 1995 4821

Bifunctional Carriers of Organometallics Table 4. Selected Bond Distances (A) and Angles (deg) for Complex b Zrl-N1 Zrl-N2 Zrl-N3 Zrl-N4 Zrl-C16 Zrl-C17 Zrl-C18 Zrl-C19 Zrl-Cp4 Zrl-C37 K1-N1 Kl-N2 Kl-N3 K1-C1 Kl-C2 Kl-C3 Kl-C4 K1-C11 Kl-C7' K1-C8' Kl-C37' Kl-C38A Kl-C38B' N1-C1 C37-Zrl-Cp4 N3-Zrl-Cp4 N3-Zr 1-C37 N2-Zrl-Cp4 N2-Zr 1-C37 N2-Zrl-N3 N1-Zr 1-Cp4 Nl-Zrl-C37 Nl-Zrl-N3 Nl-Zrl-N2 Zrl-Nl-C4 Zrl -Nl-Cl C1-N1 -C4 Zrl -N2-K1 Kl-N2-C9

2.23615) 2.259i5j 2.211(6) 2.383(5) 2.500(8) 2.620(7) 2.616(7) 2.523(6) 2.237(7) 2.271(8) 3.246(7) 3.152(6) 3.392(5) 3.535(7) 3.651(9) 3.498(9) 3.275(10) 3.438(6) 3.207(8) 3.286(10) 3.325(8) 3.460(18) 3.65(3) 1.407(8) 104.9(2) 96.9(3) 108.4(2) 166.7(2) 88.4(2) 78.9(2) 95.2(2) 111.7(3) 133.2(2) 79.2(2) 127.0(4) 121.0(4) 105.2(5) 78.7(1) 122.0(4)

N1 -C4 N2 -C6 N2 -C9 N3-Cll N3-Cl4 N4-Cl6 N4-Cl9 Cl-C2 C2-C3 c3-c4 C6-C7 C7-C8 C8-C9 Cll-c12 C12-Cl3 C13-Cl4 C16-Cl7 C17-Cl8 C18-Cl9 C37-C38A C37-C38B C38A-C39A C38B-C39B

1.388(8) 1.399(11) 1.419(8) 1.389(9) 1.405(9) 1.395(7) 1.367(9) 1.392(9) 1.409(11) 1.385(9) 1.377(10) 1.410(13) 1.381(12) 1.357(13) 1.406(11) 1.362(12) 1.402(11) 1.404(11) 1.383(9) 1.38(2) 1.37(3) 1.29(3) 1.29(4)

Kl-N2-C6 Zrl-N2-C9 Zrl-N2-C6 C6-N2-C9 Zrl -N3 -C 14 Zrl -N3 -C 11 Cll-N3-C14 Zrl -N4-C 19 Zrl-N4-C16 C16-N4-C 19 Zrl-C37-C38B Zrl-C37-C38A C37-C38A-C39A C37-C38B-C39B

120.0(4) 114.0(4) 113.4(4) 106.3(5) 120.5(4) 128.6(5) 105.1(5) 79.5(3) 78.1(3) 105.6(5) 130.6(12) 122.6(8) 135.7(19) 137.9(26)

a Cp4 refers to the centroid of the pyrrolic ring N4,C16,C17,C18,C19. The prime denotes a transformation of x , - y , 0.5 Z .

+

ties: (i) the hydrozirconation reaction1' of olefins and acetylenes using 2, and (ii) the alkali-metal ion exchange. The hydrozirconation of ethylene is shown in reaction 3.

K

Et

K

Reaction 3 occurs under relatively mild conditions and gives good yields of the corresponding potassium-alkyl derivative. Complex 7 has spectroscopic data very similar to those of [{(175:171:r1:171-EteNq)Zr-CH2CH3)2CUN a ) ~ lthe , ~ dimeric ~ structure of which was established with an X-ray analysis. Such dimeric structures are

usually broken into the monomeric species by good coordinating solvents such as THF.3c An alkali-metal ion exchange has been carried out according to reaction 4. A THF solution of 4 reacts smoothly with an equimolar amount of KH, leading t o 8.

[{(q5:q':q':q1-Et,N,)Zr-Me}{Li(THF),}l 2 KH

4 [{(q5:q':q':q'-Et,N4)Zr-Me} { K(THF),} 3 (4) 8

The solid-state structure we propose for 8 is close to that of 4 and to that of the sodium analogue, [{(q5:q1: q1:~1-Et~N4)Zr-Et}z{Na(THF)Z)l.3C We should emphasize that the occurrence of the alkali-metal-zirconium alkyl derivative as a monomer or as a dimer depends exclusively on the solvent; the dimeric form is isolated from toluene, while the monomeric form is obtained from THF solvating the alkali-metal cation.3c Another common characteristic of the alkyl derivatives of zirconium porphyrinogen thus far reported is the difference between the bonding mode of the porphyrinogen to the metal, being q5:q1:q1:q1in the solid state and q1:q5:q1:q5 in solution, as revealed by the NMR spectrum at room temperature. The reactions reported so far including those discussed above, led to the formation of Zr-H and Zr-C bonds via the addition of a polar organometallic to the bifunctional complex 1. They have involved migratory insertion reactions, which have significant precedence in cyclopentadienyl- and alkoxo-zirconium chemi ~ t r y . ~The ~ J reactions ~ of 2, 5, and 6 with ButNC parallel the known behavior of the cyclopentadienyl and alkoxo d e r i ~ a t i v e s , ~ even ~ J ~ Jthough ~ in this case we are dealing with metalate forms. However, a striking (11)Schwartz, J.;Labinger, J. A. Angew. Chem., Int. Ed. Engl. 1976, 15, 333. Cam, D. B.; Yoshifuji, M.; Shoer, L. I.; Gell, K. I.; Schwartz, J. Ann. N.Y. Acad. Sci. 1977,295, 127. Hart, D. W.; Blackburn, T. F.; Schwartz, J. J. Am. Chem. SOC.1975,97,679. Hart, D. W.; Schwartz, J. J. Am. Chem. SOC.1974,96,8115. Gibson, T. Tetrahedron Lett. 1982, 23, 157. Bock, P. L.; Boschetto, D. J.; Rasmussen, J. R.; Demers, J. P.; Whitesides, G. M. J.Am. Chem. SOC.1974,96, 2814. Labinger, J. A.; Hart, D. W.; Seibert, W. E.; Schwartz, J. J. Am. Chem. SOC.1976,97, 3851. Bertelo, C. A.; Schwartz, J. J. Am. Chem. SOC.1976, 98, 262; 1975, 97, 228. Blackburn, T. F.; Labinger, J. A.; Schwartz, J. Tetrahedron Lett. 1976,16,3041. Neghishi, E.; Yoshida, T. Tetrahedron Lett. 1980,21,1501. Neghishi, E.; Takahashi, T. Aldrichim. Acta 1986, 18,31. Neghishi, E.; Miller, J. A.; Yoshida, T. Tetrahedron Lett. 1984, 25, 3407. Jordan, R. F.; Lapointe, R. E.; Bradley, P. K.; Baenzinger, N. Organometallics 1989,8,2892 and references therein. For a survey of group IV and V hydrides, see: Toogood, G. E.; Wallbridge, M. G. H. Adv. Inorg. Chem. Radiochem. 1982,25, 267. Cardin, D. J.; Lappert, M. F.; Raston, C. L. In Comprehensive Organometallic Chemistry; Wilkinson, G., Stone, F. G. A., Abel, E. W., Eds.; Pergamon: Oxford, U.K., 1981;Vol. 3, Chapter 23.2, p 45. Schwartz, J. Pure Appl. Chem. 1980,52,733. Buchwald, S. L.; La Maire, S.J.; Nielsen, R. B.; Watson, B. T.; King, S. M. Tetrahedron Lett. 1987,28, 3895. (12) (a)Durfee, L. D.; Rothwell, I. P. Chem. Rev. 1988,88, 1059. (b) Wolczanski, P. T.; Bercaw, J. E. ACC.Chem. Res. 1980, 13, 121. ( c ) Headford, C. E. L.; Roper, W. R. In Reactions of Coordinated Ligands; Braterman, P. S., Ed., Plenum: New York, 1986, Vol. 1, Chapter 8. (13) Singleton, E.; Ossthnizen, H. E. Adv. Organomet. Chem. 1983, 22,209. Otsuka, S.; Nakamura, A.; Yoshida, T.; Naruto, M.; Ataba, K. J . Am. Chem. SOC.1973,95,3180. Yamamoto, Y.; Yamazaki, H. Inorg. Chem. 1974,13, 438. Aoki, K.; Yamamoto, Y. Inorg. Chem. 1976,15, 48. Bellachioma, G.; Cardaci, G.; Zanazzi, P. Inorg. Chem. 1987, 26, 84. Maitlis, P. M.; Espinet, P.; Russell, M. J. H. In Comprehensive Organometallic Chemistry; Wilkinson, G., Stone, F. G. A., Abel, E. W.,

Eds.; Pergamon: London, 1982; Vol. 8, Chapter 38.4. Crociani, B. In

Reactions of Coordinated Ligands; Bratennan, P. S., Ed.; Plenum: New York, 1986;Chapter 9. Ruiz, J.;Vivanco, M.; Floriani, C.; Chiesi-Villa, A.; Rizzoli, C. Organometallics 1993, 12, 1811. Hose, A.; Solari, E.; Ferguson, R.; Chiesi-Villa, A.; Rizzoli, C. Organometallics 1993, 12,

2414.

4822 Organometallics, Vol. 14,No. 10,1995

Jacoby et al.

Table 5. Selected Bond Distances (A) and Angles (deg) for Complex 10

W

Figure 4. SCHAKAL perspective view of complex 10.

difference has been observed in the case of carbon monoxide.3b The insertion of ButNC into the Zr-H and Zr-C bonds led to y2-iminoformyl, (9), and v2-iminoacetyl (lo) complexes. [{(+qI -ql-ql- E & J N ~ ) Z ~ } ~ ( ~ + - KButNC H)~]

3

7

Zrl-N1 Zrl -N2 Zrl -N3 Z r l -N4 Zrl-N5 Zrl-C16 Z r l -C 17 Zrl-C18 Zr 1-C 19 Zr 1-Cp4 Zrl-C38 Lil-01 Lil-N1 Lil-N4 Lil-C1 Lil-C2 Lil-C3 Lil-C4 N1-C1 Nl-C4 N2-C6 C38-Zrl -Cp4 N5-Zrl -Cp4 N5-Zrl-C38 N3-Zrl-Cp4 N3 -Zrl -C38 N3 -Zrl -N5 N2 -Zrl-Cp4 N2-Zrl-C38 N2-Zrl-N5 N2-Zrl-N3 N1-Zrl-Cp4 Nl-Zrl-C38 Nl-Zrl-N5 Nl-Zrl-N3 Nl-Zrl-N2 Zrl-Nl-C4 Zrl-N1-C1

2.317(2) 2.211(2) 2.202(2) 2.424(3) 2.205(2) 2.526(2) 2.666(2) 2.698(3) 2.520(3) 2.281(2) 2.195(3) 1.850(6) 2.238(6) 2.155(6) 2.241(7) 2.560(7) 2.738(7) 2.57 1(6) 1.388(3) 1.380(3) 1.397(4) 98.3(1) 114.3(1) 33.4(1) 94.0(1) 100.8(1) 125.6(1) 155.0(1) 105.8(1) 89.9(1) 75.2(1) 91.7(1) 120.3(1) 89.6(1) 137.1(1) 82.0(1) 130.0(2) 121.9(1)

N2-C9 N3-Cll N3-Cl4 N4-Cl6 N4-Cl9 N5-C38 N5-C39 Cl-C2 C2-C3 c3-c4 C6-C7 C7-C8 C8-C9 Cll-c12 C12-Cl3 C13-Cl4 C16-Cl7 C17-Cl8 C18-Cl9 C37-C38 Cl-Nl-C4 Zrl-N2-C9 Zrl-N2-C6 C6-N2-C9 Zrl -N3-C 14 Zrl-N3-C11 Cll-N3-C14 Zr 1-N4 -Li 1 Z r l -N4-C 19 Zrl-N4-C16 C16-N4-C19 Z r l -N5-C39 Zrl-N5-C38 C38-N5-C39 Zrl-C38-C37 Zrl-C38-N5

a Cp4 refers to the centroid N4,C16,C17,C18,C19.

I((q5-q 1-ql-ql-EteN4)Zr-Me)(Li(THF) 2))

4

+B u t N C T

/

Complexes 9 and 10 show very similar spectroscopic characteristics, with a single type of pyrrole in the lH NMR spectrum, two sets of triplets for the methyl groups, and a single quartet for the methylenes of the meso-ethyl groups. Although the solid-state structure of 8 shows the v1:q1:q1:q5bonding mode of the porphyrinogen, only a single type of pyrrolyl anion is observed in the lH NMR spectrum, due to the dynamic behavior of the ligand. The C=N stretching bands at 1552 cm-l (9) and 1607 cm-l (10) are in agreement with the q2bonding mode of the iminoformyl and iminoacyl which has been verified by the X-ray analysis of 10. The structure of 10 is displayed in Figure 4. The plane of the Zr-iminoacyl fragment (Zr,N5,C28) is nearly perpendicular to the N4 mean plane (dihedral angle 75.3(1)"), from which the four nitrogen atoms show significant tetrahedral distortions (Table 5). The [(EtsN4)Zr] moiety maintains the saddle-shaped con-

of the

1.389(4) 1.379(3) 1.382(3) 1.374(3) 1.394(3) 1.264(4) 1.505(5) 1.373(4) 1.395(6) 1.379(4) 1.352(4) 1.412(5) 1.364(4) 1.370(5) 1.406(5) 1.365(4) 1.400(3) 1.392(3) 1.384(4) 1.508(6) 106.9(2) 118.3(2) 125.0(2) 106.5(2) 124.6(2) 128.1(2) 107.0(2) 96.4(2) 77.4( 1) 78.0(1) 106.0(2) 155.0(2) 72.9(1) 132.0(2) 155.4(2) 73.7(1) pyrrolic ring

f~rmation~ found ~ J ~ in 5 and 6, although some distortion, indicated by the dihedral angles reported in Table 2, is induced by the bulky But substituent. The significant lengthening of the Zr-N1 distance (Table 5) and the variable displacements of zirconium from the pyrrole rings are probably due to intraligand steric interactions contact (3.414(5) giving rise to a rather short Nl***C42 A). The lithium cation is +bonded to N4 and $-bonded to Nl,Cl,C2,C3,C4, if we assume that Li-C3 = 2.736, is not too long for a bonding intera~ti0n.l~ (7) & From a commparison of reactions of Zr-H and Zr-C bonds in complexes 2-6 with olefins or isocyanides with reactions based on alkoxo- and cyclopentadienylzirconium derivatives, we have shown how we can dictate, through the use of porphyrinogen as an ancillary ligand, the syntheses and transformations of polar organometallic functionalities. Complexes 9 and 10 should be considered as polar alkali-metal iminoformyl and iminoacyl derivatives bonded to the bifunctional complex 1. The role of the alkali-metal cation can be relevant both in driving the addition of polar organometallics and in assisting their reactivity in the complexed form, as we observed in the case of the reaction with carbon monoxide.3b (14)De Angelis, S.; Solari, E.; Floriani, C.; Chiesi-Villa,A.; Rizzoli, C. J. Am. Chem. SOC.1994,116,5691,5702. (15)Weiss, E.; Dietrich, H. J. Organometal. Chem. 1987,322,299.

Bifunctional Carriers of Organometallics

Experimental Section General Procedure. All reactions were carried out under an atmosphere of purified nitrogen. Solvents were dried and distilled before use by standard methods. The synthesis of complex 1has been carried out as reported.3c The synthesis of potassium allyl has been carried out following the Schlosser procedure.16 Infrared spectra were recorded with a PerkinElmer 883 spectrophotometer; lH NMR spectra were measured on 200-AC and 400-DPX Bruker instruments. Synthesis of 2. KH (1.10 g, 27.50 mmol) was added to a toluene solution of 1 (19.30 g, 27.5 mmol). The suspension was heated to 100 "C for 2 days and then cooled t o room temperature. The resulting complex 2 is a white microcrystalline solid, which was removed by filtration, washed with toluene, and collected (88%). Crystals suitable for X-ray analysis were obtained from a dilute solution in toluene. The insolubility of the complex prevented NMR characterization. Anal. Calcd for C72HgsKzN~Zrz: C, 64.84; H, 7.41; N, 8.41. Found: C, 65.03; H, 7.32; N, 8.18. Synthesis of 3. A THF (300 mL) solution of 1 (22.04 g, 31.48 mmol) was reacted with KH (2.61 g, 65.1 mmol). The suspension was heated to 40 "C for 30 h. A very small amount of undissolved solid was removed by filtration, and the solvent was evaporated to dryness. The solid was collected using toluene (150 mL), where the complex is only slightly soluble. The yellow powder was then filtered and dried in vacuo (63%). Crystallization from THFhexane gave a crystalline yellow solid, suitable for X-ray analysis. Anal. Calcd for C184HZ80C, 62.17; H, 7.96; N, 6.31. Found: C, 62.14; H, &N1601&'4: 7.39; N, 6.65. lH NMR (THF-ds, room temperature): 6 0.42 (t, Me, 12 H), 0.47 (t, Me, 12 H), 1.80 (q, CH2, 16 H), 5.10 ( 8 , C ~ H Z N2, H), 5.80 (9, C~HZN, 6 H). Synthesis of 4. MeLi (5.0 mL, 1.6 M in EtzO, 8.00 mmol) was added in a dropwise fashion to a toluene (100 mL) and THF (5 mL) solution of 1 (4.92 g, 7.10 mmol). The mixture was stirred at room temperature for 2 h and then evaporated to dryness. The resulting light-yellow solid was dissolved with n-hexane (50 mL), and then the solution was filtered (72%). Recrystallization of the solid was carried out from an n-hexanel toluene mixture. Anal. Calcd for C45H67LiN402Zr: c, 67.97; H, 8.75; N, 7.05. Found: C, 67.60; H, 8.78; N, 6.90. 'H NMR (C6D6): 6 0.09 ( 8 , Me-Zr, 3 H), 0.82 (t, CH3, 12 H), 0.89 (t, CH3, 12 H), 1.24 (m, THF, 8 H), 2.00 (m, CH2, 16 H), 3.07 (m, THF, 8 H), 6.09 (9, C~HZN, 4 H), 6.67 (9, C ~ H Z N4, H). Synthesis of 5. BunLi (2.0 mL, 1.6 M, 3.20 mmol) was added to a toluene/THF (100 mU5 mL) solution of 1 (2.25 g, 3.20 mmol). The mixture was stirred at 50 "C for 2 h, after which time a very small amount of solid was removed by filtration and the filtrate was evaporated to dryness. The residue was dissolved in warm n-hexane (80 mL). The n-hexane solution gave light yellow crystals upon standing and cooling (80%). Anal. Calcd for C48H73LiN402Zr: C, 68.94; H, 8.80; N, 6.70. Found: C, 68.90; H, 8.77; N, 6.68. 'H NMR (CsD6): 6 0.29 (m, Bun-Zr, 2 H), 0.81 (t, CH3, 12 H), 0.89 (t, CH3, 12 H), 0.97 (t, Bun-Zr, 3 H), 1.21 (m, THF, 8 H), 1.27 (m, Bun-Zr, 2 H), 1.98 (m, CH2, 16 HI, 3.06 (m, THF, 8 HI, 6.07 (5, CIH~N,4 H), 6.72 fs, CIHZN,4 H). Synthesis of 6. Solid potassium allyl (0.93 g, 13.00 mmol) was added to a toluene (150 mL) solution of 1 (7.78 g, 12.00 mmol). The mixture was stirred at room temperature for 1h, after which time the solid formed was solubilized by heating t o 50 "C. A very small amount of solid was filtered from the warm solution. When this solution was cooled followed by addition of n-hexane, the filtrate gave yellow crystals of 6, which were dried in vacuo (75%). Anal. Calcd for C39H53KN4Zr: C, 66.14; H, 7.54; N, 7.91. Found: C, 66.13; H, 7.71; N, 7.46. IR: v(C=C) 1603 cm-'. 'H NMR (C&, 298 K, 400 (16) Schlosser, M. J. Organomet. Chem. 1967, 8, 9. Desponds, 0. Thesis Dissertation, University of Lausanne, Lausanne, Switzerland, 1991. Schlosser, M.; Desponds, 0.; Lehmann, R.; Moret, E.; Rauchschwalbe, G. Tetrahedron 1993, 49, 10175.

Organometallics, Vol.14,No. 10,1995 4823 MHz): 6 0.84 (t, CH3, 12 H, J = 7.4 Hz), 0.66 (t, CH3, 12 H, J = 7.4 Hz),1.88 (q, CH2,12 H), 2.07 (q, CHZ,4 HI, 3.00 (d, allyl CH2, 4 H, J = 11.4 Hz), 5.74 (quint, allyl CH, 1 H, J = 11.4 Hz), 5.93 (s, C ~ H Z N4, HI, 6.31 (8, C ~ H Z N4, HI. The crystals used for the X-ray analysis contain one THF molecule for every two Zr complexes. Synthesis of 7. A suspension of 2 (5.55 g, 8.30 mmol) in toluene (150 mL) was heated to 70 "C under an atmosphere of ethylene. The solid dissolved to give a yellow solution. The solution was concentrated to ca. 50 mL, and n-hexane (100 mL) was added. Complex 7 formed as a crystalline solid (72%) from this solution. Anal. Calcd for C38H53KN4Zr: C, 65.68; H, 7.69; N, 8.07. Found: C, 65.92; N, 7.89; H, 8.19. lH NMR (C&): 6 0.20 (9, CH2-Zr, 2 H, J = 7.6 Hz), 0.73 (t, CH3, 12 H), 0.84 (t,CH3, 12 H), 1.43 (t, CH3CH2-Zr, 3 H, J = 7.6 Hz), 1.90 (9, CH2, 16 H), 5.93 (s,CIHZN,4 H), 6.64 (s,CIHZN,4 H). Synthesis of 8. KH (0.09 g, 2.19 mmol) was added to a THF (50 mL) solution of 4 (1.70 g, 2.14 mmol). The yellow color turned progressively green, and the small amount of black precipitate which formed was removed by filtration. The solution was concentrated to dryness and the solid collected using n-hexane (40 mL). The yellow-green solid was then dried in vacuo (74%). Anal. Calcd for C41H5gKN40Zr: C, 65.28; H, 7.90; N, 7.43. Found: C, 65.32; N, 7.86; H, 7.29. lH NMR (C6D6, room temperature): 6 0.40 (s, Me-Zr, 3 H), 0.75 (t, Me, 12 H), 0.84 (t, Me, 12 H), 1.27 (m, THF, 2 H), 1.8-2.3 (m, CH2, 16 H), 3.30 (m, THF, 2 H), 5.97 (s, CIHZN,4 H), 6.61 (9, GH2N, 4 H). Synthesis of 9. ButNC (0.20 mL, 1.80 mmol) was added to a toluene (50 mL) suspension of 2 (1.15 g, 1.80 mmol). The suspension was stirred for 15 h to give a solution. The solvent was reduced to half of its volume, and the solution gave 9 as a microcrystalline solid containing toluene of crystallization (60%) when left t o stand in the freezer. Anal. Calcd for C4&j&"Zr: C, 68.40; H, 7.83; N, 8.31. Found: C, 68.29; H, 7.85; N, 8.33. IR (Nujol): v(C=N) 1552 cm-'. lH NMR (C6Ds): 6 0.66 (t, CH3, 12 H), 0.69 (t, CH3, 12 H), 1.07 (s,But, 9 H), 2.06 (9, CH2, 16 HI, 2.11 (s,C7Hs, 3 HI, 6.03 ( 6 , CdHzN, 8 H), 7.16 (m, C7H8, 5 H), 10.16 (s, CH=NBut, 1 H). Synthesis of 10. ButNC (0.30 mL, 2.70 mmol) was added to a toluene (100 mL) solution of 4 (2.00 g, 2.50 mmol), and the mixture was stirred for 5 h at room temperature. The solvent was reduced to two-thirds of its volume and upon addition of n-hexane (50 mL), followed by standing, gave yellow crystals of 10 (53%). Anal. Calcd for C ~ ~ H ~ ~ L ~ N ~ ~ Z I - C ~ H B C53H78LiN50Zr: C, 70.78; H, 8.74; N, 7.79. Found: C, 69.79; H, 8.43; N, 7.83. IR (Nujol): v(C=N) 1607 cm-l. 'H NMR (C6D6): 6 0.75 (t, CH3, 12 H), 1.03 (5, But, 9 H), 1.08 (t, CH3, 12 H), 1.16 (m, THF, 4 H), 1.93 (m, CH2, 16 H), 2.19 (5, Me-C-N, 3 H), 3.25 (m, THF, 4 H), 6.25 (s, CIHZN, 8 H). The crystals used for the X-ray analysis contain C7Hs in a 1:1molar ratio. X-ray Crystallography for Complexes 3, 5, 6, and 10. Suitable crystals were mounted in glass capillaries and sealed under nitrogen. The reduced cells were obtained with the use of TRACER.17 Crystal data and details associated with data collection are given in Tables 6 and S1. Data were collected at room temperature (295 K) on a single-crystal difiactometer (Enraf-Nonius CAD4 for 3,5, and 10 and Philips PWllOO for 6). For intensities and background individual reflection profiles were analyzed.ls The structure amplitudes were obtained after the usual Lorentz and polarization correction^,^^ and the absolute scale was established by the Wilson method.20 The crystal quality was tested by qj scans, which showed that (17) Lawton, S. L.; Jacobson, R. A. TRACER (a cell reduction program); Ames Laboratory, Iowa State University of Science and Technology: Ames, IA, 1965. (18)Lehmann, M .S.; Larsen, F. K. Acta Crystallogr., Sect. A: Cryst. Phys., Diffr., Theor. Gen. Crystallogr. 1974, A30, 580-584. (19)Data reduction was carried out on an IBM AT personal computer equipped with an INMOS T800 transputer. (20) Wilson, A. J. C. Nature 1942, 150, 151.

4824 Organometallics, Vol. 14, No. 10, 1995

Jacoby et al.

Table 6. Experimental Data for the X-ray DifPraction Studies on Crystalline Compounds 3,5,6, and 10 3

formula a (A) b (A)

(A)

c

a (deg)

B (de@ y (deg)

v (‘43)

2

fw space group t (“C)

A iAj ecaicd

(g ~ m - ~ )

y (cm-’)

transmnissn coeff R= W R ~ ~ GOP

5

C I E ~ H Z . ~ O & N ~ ~ O ~ C48H73LiN402Zr OZ~~ 13.240(3) 11.451(3) 19.815(9) 11.692(3) 19.876(4) 18.726(6) 72.66(2) 74.49(2) 79.78(2) 83.43(2) 78.12(2) 79.29(3) 2323.8(12) 4926(3) 2 1 836.3 3554.0 Pi (No. 2) Pi-(No. 2) 22 22 0.710 69 0.710 69 1.195 1.198 2.70 4.30 0.831-1.000 0.813-1.000 0.046 0.044 0.111 0.122 0.926 0.468

6 C ~ ~ H S ~ K N ~5C4H80 ZPO. 28.412(4) 22.334(3) 15.419(2) 90 110.66(2) 90 9155.0(25) 8 744.3 C2/c (No. 15) 22 0.710 69 1.080 3.54 0.889- 1.000 0.056 0.135 1.066

10

C46HmLiNsOzrC.1H.g 21.535(2) 12.294(2) 19.154(3) 90 96.34(1) 90 5040.0(12) 4 897.4 P21/~(NO. 14) 22 0.710 69 1.164 2.51 0.924- 1.000 0.037 0.086 0.848

R1 = ZlM’lElFol. wR2 = [ Z ( W ( ~ ) ~ E ( W F , ~ C GOF ) ~ ] ”=’ .[&lAF’12/(NO - Nv)I”Z. since the anisotropic refinement did not lead to convergence. crystal absorption effects could not be neglected. The data The C - 0 and C-C bond distances of the disordered THF were corrected for absorption using a semiempirical methodz1 for complex 6 and ABSORB22for 3, 5, and 10. The function molecules were constrained to be 1.48(1) and 1.54(1) A, respectively. In complex 6, the C38 and C39 carbon atoms of minimized during the least-squares refinement was W A R Y . Weights were applied according to the scheme w = ~ / [ U ~ ( F ~ )the ~ allyl anion were found to be disordered over two positions UP)^] (P= (Fez 2Fc2)/3)with a = 0.0000, 0.0436, 0.0648, (A, B) and isotropically refined with the site occupation factors 0.0243 for complexes 3,5,6, and 10, respectively. Anomalous given in Table S4 (supporting information). Moreover, the scattering corrections were included in all structure factor THF solvent molecule of crystallization was found to be ~alculations.2~~ Scattering factors for neutral atoms were disordered over two positions related by an inversion center taken from ref 23a for nonhydrogen atoms and from ref 24 for and was isotropically refined with a site occupation factor of H. Among the low-angle reflections no correction for secondary 0.5 with constraints imposed on the C-C and C-0 bond extinction was deemed necessary. distances. All calculations were carried out on an IBM PSY80 personal For all complexes the hydrogen atoms, except those related computer and on an ENCORE 91 computer. The structures to disordered carbon atoms, which were ignored, were located were solved by the heavy-atom method starting from threefrom difference Fourier maps. They were introduced in the dimensional Patterson maps using the observed reflections. subsequent refinements as fixed atom contributions with U’s Structure refinements were based on the unique observed data kept at 0.10 for 3, 5, and 6 and 0.08 for 10. The final for 5,6, and 10 and on the total data for 3 using SHELX92.zs difference maps showed no unusual features, with no signifiRefinement was first done isotropically and then anisotrocant peak above the general background. Final atomic coorpically for all non-H atoms, except for some of the disordered dinates are listed in Tables S2-S5 for non-H atoms and in atoms. The structures of complexes 5 and 10 were refined Tables S6-S9 for hydrogens. Thermal parameters are given straightforwardly. In complex 3, the C61 and C62 carbons of in Tables S10-S13, bond distances and angles in Tables S14an ethyl group were found to be statistically distributed over S17.26 two positions (A, B) with a site occupation factor of 0.5. Four

+

+

Az

of the five THF molecules (Ol-C8O...C83, 02-C84*..C87, 03-C88*..C91, 05-C96*..C99) were found to be heavily affected by conformational disorder. The best fit was obtained by splitting the C81, C82, C85, C86, C88, C89, C90, C91, C96, C97, and C98 carbons over two positions (A, B) with a site occupation factor of 0.5. The C81B, C96A, C96B, C97A, C97B, C98A, C98B, and C99 positions were isotropically refined, (21) North, A. C. T.; Phillips, D. C.; Mathews, F. S.Acta Crystallogr., Sect. A: Cryst. Phys., Diffr., Theor. Gen. Crystallogr. 1968, A24, 351. (22) Ugozzoli, F. ABSORB,a Program for F,Absorption Correction. In Comput. Chem. 1987,11, 109. (23) (a) International Tables for X-ray Crystallography; Kynoch Press: Birmingham, U.K., 1974; Vol. IV,p 99. (b) Zbid., p 149. (24) Stewart, R. F.; Davidson, E. R.;Simpson, W. T. J.Chen. Phys. 1966, 42, 3175. (25) Sheldrick, G. M. SHELXL92 Gamma Test: Program for Crystal Structure Refinement; University of G6ttingen, Criittingen, Germany, 1992.

Acknowledgment. We thank the “Fonds National Suisse de la Recherche Scientifique” (Grant No. 2040268.94) and Ciba-Geigy SA (Basel, Switzerland) for financial support. Supporting Information Available: Tables of experimental details associated with data collection and structure refinement, final atomic coordinates for non-H atoms, hydrogen atom coordinates, thermal parameters, and bond distances and 10 (38pages). and angles and ORTEP drawings for 3,5,6, Ordering information is given on any current masthead page. OM9503398 (26) See paragraph at the end regarding supporting information.