Indenyl Ring Research Articles

Synthesis and crystal structure of (C 9H 7GdCl 2 · 3THF)THF

The indenylgadolinium dichloride tristetrahydrofuranate (C 9H 7GdCl 2 · 3THF)THF was prepared and its crystal structure (monoclinic space group P2 1) determined by X-ray diffraction. In C 9H 7GdCl 2 ·. 3THF, Gd, O(1), O(2), O(3) and the centroid of the five-membered indenyl ring form a plane, and Cl(1) and Cl(2) are located at two opposite sides of the plane to give a pseudooctahedron. The coordination number of Gd is eight.

Flexible coordination of indenyl ligands in sandwich complexes of transition metals. Molecular structures of [(η-C 9R 7) 2M] (M = Fe, R = H, Me; M = Co, Ni, R = H): Direct measurement of the degree of slip-fold distortion as a function of d-electron count

The crystal and molecular structures of [(η-C 9H 7) 2M] (M = Fe, 1; Co, 2; Ni, 3) and [(η-C 9Me 7) 2Fe], 4, are reported, along with a discussion of the correlation between hapticity and the 13C chemical shift of the indenyl ring-junction carbons (C(3a), C(7a)). Single crystals of both 1 and 2 undergo non-destructive and reversible phase changes upon cooling below ca. 240–245 K. The room-temperature structures are disordered; however, the low temperature ones (150 K) are essentially ordered. Crystals of 3 do not display this behavior on cooling to 150 K, and residual anisotropy in certain carbon atoms is ascribed to a minor twinning problem. Crystals of 4 were only examined at ambient temperature, where an ordered structure was obtained. In contrast to the analogous Cp 2M series (Cp = η 5-C 5H 5; M = Fe, Co, Ni), which display a gradual symmetric increase in MC distances in the order Fe < Co < Ni, the distortions in the indenyl series are of a fundamentally different nature. Thus, there is a gradual increase in the degree of slip-fold distortion from η 5- toward η 3-coordination which involves (a) slippage of the metal away from C(3a),C(7a), and (b) folding of the ring system (particularly at C(1),C(3)), in the order Fe < Co < Ni. The slip values (Δ = avg d(MC(3a),C(7a)) − avg d(MC(1),C(3)) are 0.043(4), 0.124(4), 0.418(6), and 0.030(4) Å for 1– 4, respectively. For a “true η 5”-complex, Δ should be ca. 0 Å, whereas values of ca. 0.69–0.79 Å have been reported for “true η 3-”indenyl complexes such as [(η 3-C 9H 7)Ir(PMe 2Ph) 3]. Therefore, complexes 1 and 4 are clearly η 5, as predicted on the basis of the 18-electron rule, whereas 2 and 3 display increasing degrees of distortion in both rings to avoid 19- and 20-electron counts, respectively. The two indenyl rings in 3 are half-way between η 5- and η 3-coordination modes. Crystal data for 1 at 295 K are: monoclinic, P2 1 n , a 8.030(2), b 7.806(2), c 10.779(2) Å, β 107.39(1)°, V 648.9(2) Å 3, Z = 2, structure not refined; at 150 K: monoclinic, Cc, a 16.021(4), b 15.510(5), c 11.187(3) Å, β 115.53(2)°, V 2509(1) Å 3, Z = 8, R = 0.0306, R w = 0.0332. For 2 at 295 K: monoclinic, P2 1 n , a 8.027(2), b 7.838(2), c 10.936(3) Å, β 107.57(2)°, V 655.9(2) Å 3, Z = 2, structure not refined; at 150 K: monoclinic, P2 1 c , a 11.258(3), b 7.824(3), c 15.256(6) Å, β 108.07(2)°, V 1277.7(7) Å 3, Z = 4, R = 0.0397, R w = 0.0447. For 3, at 150 K: monoclinic, P2 1 n , a 6.063(1), b 20.056(3), c 10.703(2) Å, β 94.27(1)°, V 1297.9(3) Å 3, Z = 4, R = 0.0413, R w = 0.0493. For 4, at 295 K: orthorhombic, Pbcn, a 14.211(2), b 9.284(2), c 19.289(4) Å, V 2544.8(8) Å 3, Z = 4, R = 0.0410, R w = 0.0421.

Substituted cyclopentadienyl complexes. Part 4. The catalysed synthesis and proton nuclear magnetic resonance spectra of [Ru(η5-C5H4Me)(CO)(L)I] and [Ru(η5-C9H7)(CO)(L)I](L = phosphine or isocyanide) and the crystal structure determination of [Ru(η5-C9H7)(CO){P(CH2Ph)3}I

The reaction between [Ru(η5-C5H4Me)(CO)2I] and L [L = P(OMe)3, P(OEt)3, P(OPri)3, PPh3, PMe2Ph, ButNC, or 2,6-Me2C6H3NC] or [Ru(η5-C9H7)(CO)2I] and L [L = P(OMe)3, P(OEt)3, P(OPri)3, P(OC6H4Me-o)3, PPh3, or P(CH2Ph)3] in the presence of [{Fe(η5-C5H5)(CO)2}2] as catalyst yields the new substituted products [Ru(η5C5H4Me)(CO)(L)I], (1) and [Ru(η5-C9H7)(CO)(L)I], (2). The new products have been characterized by a combination of i.r. and n.m.r. spectroscopy and mass spectrometry. Ring proton resonances of complexes (1) have been assigned by nuclear Overhauser enhancement (n.O.e.) spectra [L = P(OMe)3, PMe2Ph, PMePh2, or 2,6-Me2C6H3NC]. The n.O.e. spectra also reveal preferential conformations of the cyclopentadienyl ring when L is large. Such spectra were also recorded for complexes (2)[L = P(OC6H4Me-o)3 or P(CH2Ph)3] and together with coupling constant data are consistent with a ligand orientation in which L = P(CH2Ph)3 is found preferentially under the central carbon atom of the cyclopentadienyl indenyl ring. This was further confirmed by a crystal structure determination of [Ru(η5-C9H7)(CO){P(CH2Ph)3}I]·0.5C6H6: space group P, Z= 2, a= 9.923(2), b= 11.055(4), c= 14.543(3)A, α= 84,52(2), β= 77.72(2), γ= 82.74(2)°, and R= 0.0560.

Some Cyclopentadienyl and Indenyl Niobium(V) Phenoxides

AbstractSome cyclopentadienyl and indenyl niobium(V) phenoxides are reported in this communication. The effect of different types of groups in the phenoxide ring is related with the stability of the compounds. It has been established that only those phenols which have two hydroxyl groups in the ortho position are able to form chelates. The cyclopentadienyl and the indenyl rings are π‐bonded to niobium atom. The complexes have been characterised by elemental analysis and i.r. spectra.

Insertion reactions of diazoindene with some rhodium and manganese halides

Diazoindene inserts into the rhodium-chlorine bond in [CODRhCl] 2, where COD = 1,5-cyclooctadiene, to give (η 5-1-C 9H 6Cl)RhCOD. Similar complexes could not be isolated from [Rh(CO) 2Cl] 2 and [Rh(CO)PPh 3)Cl] 2. This was attributed to the labilizing ability of the indenyl ring and the absence of a chelating ligand. The complexes Mn(CO) 5X, where X = Cl, Br and I, react with diazoindene to give (η 5-1-C 9H 6X)Mn(CO) 3. Only the pentahapto bonding mode was observed for the indenyl ligand. The reactions of complexes of the type Mn(CO) 5−nL nX, where L = phosphine or phosphite, X = Cl or Br, and n = 1 or 2, were investigated. Cis-Mn(CO) 4PPh 3Br loses a carbonyl and the phosphine to give (η 5-1-C 9H 6Br)Mn(CO) 3.

The stereospecific ring protonation of diindenyliron

Reactions of protonic acids (HCl, CF 3COOH) with diindenyliron give the h 5-indenyl- h 6-indeneiron(II) monocation, [Fe(C 9H 7)(C 9H 8)] +, which can be isolated as a hexafluorophosphate salt. Two deuterium labeling experiments, the reaction of Fe(C 9H 7) 2 and DCl and the reaction 1,1′,3,3′-tetradeuteriobis(indenyl)iron with HCl, confirm that the products in this reaction have been formed by stereospecific addition of the proton to the indenyl ring. Because of the wealth of data on metal protonations, including data on the protonation of ferrocene at the iron atom, preference is indicated here for endo ring protonation which is proposed to occur via an intermediate protonated metal species. Protonation of Fe(C 5H 5)(C 9H 7) is also reported. Deprotonation with n-butyllithium regenerates diindenyliron. However, data on these reactions suggest preferential loss of an exo-proton, which is perhaps realistic in view of the known attack of nucleophiles on the exo position of coordinated hydrocarbon rings.