Tp Me2 Research Articles

Heterolytic H2 activation by rhodium thiolato complexes bearing the hydrotris(pyrazolyl)borato ligand and application to catalytic hydrogenation under mild conditions

Thiolato complexes of Rh(III) bearing a hydrotris(3,5-dimethylpyrazolyl)borato ligand (Tp(Me2)) have been prepared, and their reactivity toward H(2) has been investigated. The bis(thiolato) complex [Tp(Me2)Rh(SPh)(2)(MeCN)] (1) reacted with 1 atm H(2) at 20 degrees C to produce the hydrido-thiolato complex [Tp(Me2)RhH(SPh)(MeCN)] (2) and PhSH via heterolytic cleavage of H(2). This process is reversible and in equilibrium in THF and benzene. The bis(selenolato) complex [Tp(Me2)Rh(SePh)(2)(MeCN)] (4) was also converted to [Tp(Me2)RhH(SePh)(MeCN)] and PhSeH under 1 atm H(2), but the equilibrium largely shifted to 4. Reaction of the dithiolato complex [Tp(Me2)Rh(bdt)(MeCN)] (3; bdt = 1,2-C(6)H(4)S(2)) with H(2) occurred in the presence of amine, giving the anionic hydrido complex [Tp(Me2)RhH(bdt)](-) and an equimolar amount of ammonium cations. Catalytic activity for hydrogenation has been examined under 1 atm H(2) at 20-50 degrees C. While 1, 2, and 4 slowly hydrogenated styrene at similar rates at 50 degrees C, activities for the hydrogenation of N-benzylideneaniline increased in the order, 2 < 1 < 4. Complex 3 was found to be the most active and selective catalyst for hydrogenation of imines, and thus a variety of imines were reduced at 20 degrees C under 1 atm H(2), with the C=C and C=O bonds in the substrate molecules completely preserved. An ionic mechanism was involved to explain such high chemoselectivity.

Redox and catalytic properties of alkoxides based on tris(3,5-dimethylpyrazolyl)borato tungsten nitrosyls

Abstract Previously we reported on the catalytic properties of species based on the {Mo(NO)(Tp Me2 )O 2 } moiety in the cathodic reduction of chloroform. Here, we have performed cyclic voltammetry and spectroscopic studies of the tungsten bis -alkoxide [W(NO)(Tp Me2 )(OEt) 2 ], a novel chelate [W(NO)(Tp Me2 )O(CH 2 ) 4 O], and a mono -alkoxide [W(NO)(Tp Me2 )Cl(OEt)] [Tp Me2 = hydrotris(3,5-dimethylpyrazol-1-yl)borate]. All these complexes efficiently catalyse the cathodic reduction of chloroform which proceeds even at ca. −1.77 V versus Fc + /Fc in the presence of the chloro(ethoxy) complex. The chelate complex exhibits a quasi-reversible one-electron reduction at a potential 180 mV more anodic than its bis(ethoxy) counterpart. The UV–Vis spectrum of the former complex shows a red-shifted band (by 70 nm) in the visible region when compared with the latter.

Molybdenum doubly bridged and chelate nitrosyl complexes incorporating saturated n-alkanediolate ligands

The redox-active doubly bridged species [{Mo(NO)(Tp Me2)Q} 2] [Tp Me2 = tris(3,5-dimethylpyrazol-1-yl)hydroborate, Q = O(CH 2) n O, n = 3, 5, or OCH 2(CF 2) n− 2CH 2O, n = 5, 6], and a chelate complex [Mo(NO)-(Tp Me2)O(CH 2) 5O] were prepared and characterised by elemental and mass analyses, 1H NMR and IR spectroscopy. The bimetallic species with C 3, C 5, and C 5(F) bridges exhibit two well-resolved reduction processes in their cyclic voltammograms (Δ E 1/2 values of 290, 170, and 170 mV, respectively). These results indicate that the presence of the second bridge increases the extent of electrochemical interactions (by ca. 90–130 mV) in comparison with their singly bridged analogues. All non-fluorinated and the chelate species were catalytically active in cathodic reduction of chloroform.

A high-spin Fe(II)/low-spin Fe(III) redox couple featuring the hydro[tris(4-chloro-3,5-dimethyl-pyrazolyl)]borate ligand: Synthesis, spectroscopic and X-ray crystallographic characterization

The white homoleptic high-spin iron(II) complexes Fe[Tp Me2,4Cl] 2 ( 1) was isolated in quantitative yield from reaction mixtures containing 1 equiv of FeCl 2(THF) 1.5 and 2 equiv of K[Tp Me2,4Cl] (Tp Me2,4Cl = hydrotris[(4-chloro-3,5-dimethyl-pyrazolyl)]borate). Its purple low-spin iron(III) counterparts 1[O 3SCF 3] and 1[PF 6] were synthesized and isolated in 85% yields upon treatment of 1 with 1 equiv of silver triflate and silver hexafluorophosphate, respectively. The three paramagnetic compounds are air and thermally stable as solids and in solution; they were characterized by elemental analyses, IR, magnetic susceptibility measurements, 1H NMR, and Mössbauer spectroscopy. In addition, 1[PF 6] was authenticated by a single-crystal X-ray diffraction. The two scorpionate ligands are κ 3-N,N′,N′′ ligated to the central Fe III ion, forming an almost perfect FeN 6 octahedron with an average Fe–N bond distance of 1.9551(18) Å. In addition, complex 1 which oxidizes reversibly at E 1/2 = 0.483 V/SCE (Δ E p = 94 mV), remains high-spin (S = 2) when the temperature is lowered to 2 K.

Synthesis of Mixed Cp/TpMe2 Lanthanide Complexes from Lanthanocene Precursors and their Structures and Reactivities

Reaction of Cp(2)LnCl with 1 equiv of KTp(Me2) in toluene gives the mixed Tp(Me2)/Cp lanthanide complexes Cp(2)Ln(Tp(Me2)) (Ln = Yb (1a), Er (1b), Dy (1c)), while unexpected complexes CpLn(Tp(Me2))Cl(THF) (Ln = Yb (2a), Er (2b.THF), Dy (2c), Y (2d)) are obtained when the reactions are carried out in THF. Complex 2b can also be formed by the reaction of CpErCl(2)(THF)(3) with 1 equiv of KTp(Me2) in THF. Moreover, complex 1a can also be obtained from the reaction of Cp(3)Yb and KTp(Me2). The results not only represent an efficient and versatile method for the synthesis of mixed Cp/Tp(Me2) lanthanide complexes but also provide new insight into the reactivity of Cp(2)LnCl. Furthermore, the reactivities of complexes 1a-c toward proton-donating reagents are examined. It has been found that 1b reacts with benzotriazole (C(6)H(4)NHN(2)) in THF to yield a lanthanide metallomacrocyclic complex [(Tp(Me2))CpEr(mu-N(3)C(6)H(4))](3) (3), while the reaction of 1a with 1 equiv of 2-aminopyridine in THF gives an unexpected oxide complex [(Tp(Me2))Yb(2-HNC(5)H(4)N)](2)(mu-O) (4). Presumably, the oxide ligand of compound 4 results from adventitious water. In addition, treatment of 1c with 2 equiv of 3,5-dimethylpyrazole yields a completely Cp-abstracted product (Tp(Me2))Dy(Pz(Me2))(2)(THF) (5), which can also be directly obtained from a three-component reaction of Cp(2)DyCl, KTp(Me2), and 3,5-dimethylpyrazole in THF. These results further indicate that the new mixed Tp(Me2)/Cp lanthanide complexes are practical and versatile precursors for the synthesis of poly(pyrazolyl)borate lanthanide derivatives. All new compounds have been characterized by elemental analysis and spectroscopic methods. The structures of complexes 1a,b and 2-5 have also been determined through single-crystal X-ray diffraction analysis.

Azide-selective sensor based on tripodal iron complex for direct azide determination in aqueous samples

A potentiometric azide-selective sensor based on the use of iron(III) hydrotris(3,5-dimethylpyrazolyl)borate acetylacetonate chloride [Tp(Me2)Fe(acac)Cl] as a neutral carrier for an azide-selective electrode is reported. Effect of various plasticizers, viz. o-nitrophenyloctyl ether (o-NPOE), dioctylphthalate (DOP), dibutylphthalate (DBP), and benzylacetate (BA), and an anion excluder, hexadecyltrimethylammonium bromide (HTAB), with [Tp(Me2)Fe(acac)Cl] complex in poly(vinyl chloride) (PVC) were studied. The best performance was obtained with a membrane composition of [Tp(Me2)Fe(acac)Cl]/HTAB/DOP/PVC in a ratio of 5:2:190:100 (w/w). The sensor exhibits significantly enhanced selectivity toward azide ions over the concentration range 6.3 x 10(-7) to 1.0 x 10(-2) M with a lower detection limit of 3.8 x 10(-7) M and a Nernstian slope of 59.4 +/- 1.1 mV decade(-1). Influences of the membrane composition, pH and possible interfering anions were investigated on the response properties of the electrode. Fast and stable response, good reproducibility, long-term stability and applicability over a wide pH range (3.5-9.0) are demonstrated. The sensor has a response time of 14 s and can be used for at least 45 days without any considerable divergence in the potential response. The proposed electrode shows fairly good discrimination of azide from several inorganic and organic anions. It was successfully applied to the direct determination of azide in orange juice, tea extracts and human urine samples.

Electrochemical interactions in binuclear molybdenum and tungsten nitrosyl complexes incorporating saturated n-alkanediolate bridging ligands. Crystal structures of [Mo(NO)(Tp Me2)I{O(CH 2) 2OCOCH 3}] and [W(NO)(Tp Me2)I 2] · 0.5I 2 · 0.5C 6H 5CH 3

A series of bimetallic ([{M(NO)(Tp Me2)X} 2(Q)] [Tp Me2 = tris(3,5-dimethylpyrazolyl)borate; M = Mo, X = Cl, Q = O(CH 2) n O, n = 3, 5, 6, or OCH 2(CF 2) 3CH 2O; M = Mo, X = I, n = 3 or 4; M = W, X = Cl, n = 3–6, or OCH 2(CF 2) 3CH 2O; M = W, X = Br, n = 2]), and a number of monometallic complexes (M(NO)(Tp Me2)X(QH)] [M = Mo, X = Cl, Q = O(CH 2) n O, n = 3, or OCH 2(CF 2) 3CH 2O; M = W, X = Br, n = 2]) were prepared. The heterobimetallic complex [{Mo(NO)(Tp Me2)Br}O(CH 2) 2O{W(NO)(Tp Me2)Br}] was also obtained. All compounds were characterised by elemental and mass analyses, 1H NMR and IR spectroscopy. Electrochemical studies (CV and DPV) of the bimetallic species reveal that the metal–metal interactions decrease by ca. 100 mV per CH 2 group with increased length for C 2 to C 4 bridges and become undetectable for complexes with bridges longer than C 4. The substitution of fluorine into the C 5 bridge causes the effect to become measurable due to easier polarisation of the σ-bond framework. The crystal structures of [Mo(NO)(Tp Me2)I{O(CH 2) 2OCOCH 3}] and [W(NO)(Tp Me2)I 2] · 0.5I 2 · 0.5C 6H 5CH 3 were determined.

Critical Role of the Correlation Functional in DFT Descriptions of an Agostic Niobium Complex.

In previous studies of the agostic bonding in Tp(Me2)NbCl(R'CCR' ')(R), we have made use of a hybrid QM/MM protocol (B3LYP:UFF) where the QM partition ([Nb(Cl)(iPr)(HCCH)(NHCH2)3](+)) was rather small, but the optimized structures were nevertheless in apparently good agreement with experiment. In attempting to improve this model by expanding the size of the QM region, we were surprised to discover that a full QM treatment of the whole molecule using the B3LYP functional failed to locate an agostic structure of any kind. A systematic assessment of density functionals reveals that the poor performance of B3LYP in these systems is typical of all DFT methods that do not obey the uniform electron gas (UEG) correlation limit. Those that do obey the UEG limit, in contrast, provide an excellent description of the agostic structure when the complete ligand system is treated at the QM level. The apparently good performance of our original (B3LYP:UFF) hybrid method can be traced to a cancellation of errors: the B3LYP functional underestimates the intrinsic strength of the agostic interaction relative to competing Nb-Cl π bonding, but this is offset by an additional but unphysical electrostatic component to the agostic bond introduced by the presence of a positive charge in the QM region.

Redox activity of bimetallic complexes based on tris(3,5-dimethylpyrazolyl)borato molybdenum(II) and tungsten(II) nitrosyls. Complexes derived from ethane-1,2-diol and the crystal structure of anti-[Mo(NO){HB(3,5-Me 2C 3HN 2) 3}(OCH 2CH 2O)] 2 · 4CHCl 3

The bimetallic complexes [{M(NO)(Tp Me2)X} 2(OCH 2CH 2O)] [Tp Me2 = HB(3,5-Me 2C 3HN 2) 3; M = Mo, X = Cl, Br or I; M = W, X = Cl] have been synthesised and characterised spectroscopically and electrochemically. These species can occur as mixture of two diastereoisomers and one of them could be separated following a thermal treatment of the mixture. A direct synthesis of single diastereoisomers (M = Mo, X = I; M = W, X = Cl) is also described. The bimetallic species exhibit two one-electron reduction processes separated by a modest potential difference, Δ E 1/2, ca. 300 mV (M = Mo, X = Cl, Br) indicating an intermediate metal–metal interaction. In the crystal structure of anti-[{Mo(NO)(Tp Me2)(OCH 2CH 2O)} 2] · 4CHCl 3 two nonequivalent dinuclear molecules (point group C 2 h ) are found, with crystallographically identical, doubly bridged {Mo(NO)(Tp Me2)} distorted octahedral units.

Synthesis and structural characterization of sterically crowded hydridotris(pyrazolyl)borato complexes: Unusual double 1,2-borotropic shift at a titanium centre

The potassium and thallium(I) derivatives of the hydrido-tris(3-Me 2Bz,5-Me-pyrazol-1-yl)borato ligand, K[Tp Me2 Bz,Me] ( 1) and Tl[Tp Me2 Bz,Me] ( 2), are reported. Their reactions with TiCl 4 under mild conditions afforded, after rearrangement of the ligand, recognized as a double 1,2-borotropic shift, the related Ti(IV) complex {hydrido-[bis(3-Me,5-Me 2Bz)(3-Me 2Bz,5-Me)-pyrazol-1-yl]borato}trichlorotitanium(IV), [Tp Me2 Bz,Me∗∗] TiCl 3 ( 3). The 1H- and 13C NMR spectra of the new compounds are discussed, the molecular structure of 3 has been determined by X-ray diffraction methods, the titanium centre has a pseudo-octahedral coordination, with the nitrogen and chloride ligands in a fac geometry. A possible mechanism of formation of 3 is proposed.

Structure and bonding in a cyclobutyl tris(pyrazolyl)boratoniobium complex and the variation in agostic behaviour with ring size in the series TpMe2NbCl(c-CnH2n − 1)(MeCCMe), n = 3–6

The synthesis and characterisation of the cyclobutyl complex Tp(Me2)NbCl(c-C4H7)(MeC[triple bond]CMe) completes the family of cycloalkyl complexes Tp(Me2)NbCl(c-C(n)H(2n-1)), n = 3-6. The properties of the cyclobutyl complex are qualitatively similar to those of its cyclopentyl and cyclohexyl analogues, and dramatically different from those of the cyclopropyl derivative. Most conspicuously, the cyclobutyl system has an alpha-C-H agostic interaction in the dominant isomer, with no evidence for the alpha-C-C agostic character found for the smaller ring. C-C agostic character therefore seems to be unique to the cyclopropyl complex, where the acute C-C-C angles destabilise the C-C bonding orbitals.

Synthesis of η4:π2-Exocyclic-Diene Iridium(I) Complexes Derived from 1,3-Oxazolidin-2-ones and Their Transformation into Iridium(III) Derivatives by Reaction with a Phosphine and with Aldehydes

The reaction of the dimer [Ir(μ-Cl)(coe) 2 ] 2 with two exocyclic dienes like N-substituted 4,5-dimethylene-2-oxazolidinones a and b, and KTp Me2 yields derivatives of the composition Tp Me2 Ir( a or b) (1a,b). Derivative la reacts with Ph 2 PC≡CPPh 2 , with the formal oxidative addition of the diene moiety to the metal center and coordination of the phosphine in the k 1 mode. Derivatives 1a,b react with aromatic aldehydes to form the new compounds 3 (with benzaldehyde) and 4 (anisaldehyde), which contain an elaborated bidentate ligand formed by coupling of the two organic fragments (diene and aldehyde). The structures of compounds 3a,b have been determined by X-ray diffraction analysis.

Synthesis and characterization of uranium(III) compounds supported by the hydrotris(3,5-dimethyl-pyrazolyl)borate ligand: Crystal structures of [U(Tp Me2) 2(X)] complexes (X = OC 6H 2-2,4,6-Me 3, dmpz, Cl)

Reaction of [U(Tp Me2) 2(NR 2)] (R = Ph, SiMe 3) with protic substrates such as 2,4,6-trimethylphenol (HOC 6H 2-2,4,6-Me 3), 3,5-dimethylpyrazole (Hdmpz), 2-mercaptopyridine (HSC 5H 4N) and phenylacetylene (HCCPh) afforded the corresponding [U(Tp Me2) 2(OAr)] (Ar = C 6H 2-2,4,6-Me 3) ( 1), [U(Tp Me2) 2(dmpz)] ( 2), [U(Tp Me2) 2(η 2-SC 5H 4N)] ( 3), and [U(Tp Me2) 2(CCPh)] ( 4) compounds. Reaction of [U(Tp Me2) 2(NR 2)] with Me 3SnCl or Me 3SiBr gave [U(Tp Me2) 2Cl] ( 5) and [U(Tp Me2) 2Br] ( 6), respectively, in high yield. The amido precursors failed to react with cyclopentadiene, but metathesis of [U(Tp Me2) 2I] with NaCp yielded [U(κ 3-Tp Me2)(κ 2-Tp Me2)(η 5-Cp)] ( 7). Thermolysis of 7 resulted in oxidation of the metal centre and redistribution of the ligands, giving [UCp 3(dmpz)] ( 8), pyrazabole ( 9) and [U(Tp Me2)(dmpz) 3] ( 10). The complexes have been fully characterized by spectroscopic methods and the structures of 1, 2, and 5 were confirmed by X-ray crystallographic studies. In the solid state the complexes exhibit distorted pentagonal bipyramidal geometries.

The uranium–nitrogen bond in U(iv) complexes supported by the hydrotris(3,5-dimethylpyrazolyl)borate ligand

Insertion of benzonitrile and acetonitrile into the U-C bond of [U(Tp(Me2))Cl(2)(CH(2)SiMe(3))](Tp(Me2)= HB(3,5-Me(2)pz)(3)) gives the ketimide complexes [U(Tp(Me2))Cl(2){NC(R)(CH(2)SiMe(3))}](R = Ph (1); Me (2)). The identity of complex was ascertained by a single-crystal X-ray diffraction study. In the solid state exhibits octahedral geometry with a short U-N bond length to the ketimide ligand. We also report herein the synthesis and the X-ray crystal structures of the uranium amide complexes [U(Tp(Me2))Cl(2)(NR(2))](R = Et (3); Ph (4)). A detailed comparison of the U-N bond lengths in these compounds with other known U-N (and Th-N) distances in amide and ketimide actinide(IV) complexes is performed, confirming the short character of the U-N bond length in 1.

Synthesis and reactivity in salt metathesis reactions of trivalent [La(Tp Me2) 2X] (X = Cl, I) complexes: crystal structures of [La(Tp Me2) 2Cl] and [La(Tp Me2) 2(κ 2-pz Me2)

Reaction of LaX 3(THF) n (X = Cl, I) with two equiv. of K(Tp Me2) gave good yields of the bis-Tp complexes [La(Tp Me2) 2X] (X = Cl ( 1); I ( 3)). However, the formation of 1 and 3 is always accompanied by significant amounts of La(Tp Me2) 2(κ 2-pz Me2) ([pz Me2] − = 3,5-dimethyl-pyrazolato) ( 2). The pyrazolato complex 2, which presumably arises from decomposition of the [Tp Me2] − moiety during salt metathesis, was independently prepared in good yield from 1 and in situ generated [pz Me2] −. The solid-state structures of 1 and 2 were determined by single-crystal X-ray diffraction studies. Subsequent reactions of halogeno-Tp Me2 complexes 1 and 3 with various alkali metal salts MR (M = Li, R = CH 2SiMe 3, Ph, N(SiMe 3) 2; M = K, R = OAr) gave M(Tp Me2) as the major product. Alternatively, the mono-Tp bis(aryloxide) derivatives [Ln(Tp Me2)(OC 6H 2-2,6- t Bu-4-Me) 2] (Ln = La ( 4); Nd ( 5)) were obtained in high yields by salt metathesis of [Ln(OC 6H 2-2,6- t Bu-4-Me) 3] with one equiv. of K(Tp Me2).

NO to NO 2− conversion by divalent lanthanides: synthesis and crystal structure of [Sm(Tp Me2,4-Et) 2NO 2

The reaction of nitric oxide with the divalent lanthanide complex [Ln(Tp Me2) 2] and [Ln(Tp Me2,4-Et) 2] (Ln = Sm, Eu, Yb) gives the corresponding seven-coordinate nitrites [Ln(Tp Me2,X) 2NO 2] in a smooth reaction. A possible mechanism is proposed for this NO disproportionation. A single crystal X-ray diffraction study of [Sm(Tp Me2,Et) 2NO 2] reveals a dodecahedral metal centre. However, as is customary for these species, the complex is fluxional in solution by NMR even at the lowest accessible temperatures.

Tris-pyrazolylborate complexes of redox inactive lanthanides – the structures of [(Tp Me2) 2NdX] (X=Cl, NPh 2, dpm, H 2BEt 2)

A range of complexes of Ce and Nd have been prepared to compare the chemistry of the non-reducible [(Tp Me2) 2LnX] (Ln=Ce, Nd) with that reported previously for the redox-active samarium ion. The chloride [(Tp Me2) 2NdCl] is a useful starting material for the preparation of the seven coordinate [Nd(Tp Me2) 2OAr] (Ar=C 6H 4-4-X; X=H, Bu t , Br, Ph, OMe, F, Me) and [Nd(Tp Me2) 2NPh 2]. Crystal structures of [Nd(Tp Me2) 2Cl] and [Nd(Tp Me2) 2NPh 2] are isostructural with those of the analogous samarium species. The eight coordinate species [Nd(Tp Me2) 2(β-dike)] (β-dike=(RCO) 2CH, R=Me, Ph; Bu t ) and their cerium analogues (R=Ph, Bu t ) have also been prepared. The complexes are fluxional, the extent of this behaviour depending on the steric bulk of the substituents. The structure of [Nd(Tp Me2) 2(Bu t CO) 2CH] has been determined. Finally, in efforts to prepare a neodymium hydride, the unexpected borohydride [Nd(Tp Me2) 2(H 2BEt 2)] has been isolated serendipitously and structurally characterized.

Mono and dinuclear hydrotris(3,5-dimethylpyrazolyl)borato tantalum complexes

In an effort to obtain suitable starting materials, the synthesis and crystal structure of hydrotris(3,5-dimethylpyrazolyl)borato (Tp Me2) tantalum(III) complexes are reported. Reaction of KTp Me2 with [TaCl 2(tht)] 2(μ-Cl) 2(μ-tht) ( 1) (tht=tetrahydrothiophene) gives the X-ray characterized unsymmetrical (Tp Me2Ta)(TaCl 3)(μ-Cl 2)(μ-tht) ( 2) in fair yield. This doubly bonded TaTa complex [2.6791(5) Å, diamagnetic, 18e per Ta] is a rare example of an unsymmetrical Ta 2X 6L 3 complex. The X-ray structure of Tp Me2TaCl 2(PhCCMe) ( 3) is also reported. It has the (4e)-alkyne in the symmetry plane of the molecule. The trans effects of tht and phenylpropyne are discussed. 1 is inert towards the reaction with a second equivalent of KTp Me2.

Iridium solutes effect C-H bond activation and C-C bond forming reactions of C6H6-MeOCH2CH2OMe solvent mixtures.

The in situ generated [Tp(Me2)Ir(C(6)H(5))(2)] fragment induces both aromatic and aliphatic C-H bond activation reactions, along with C-C bond formation, when heated with benzene and 1,2-dimethoxyethane.

Coordination of 2,2'-bipyridyl and 1,10-phenanthroline to yttrium and lanthanum complexes based on a scorpionate ligand.

Reaction of yttrium and lanthanum trichloride with 1 equiv of sodium or potassium hydrotris(3,5-dimethylpyrazolyl)borate and 1 equiv of 2,2'-bipyridine gives good yields of the complexes [MCl(2)(Tp(Me2))(C(10)H(8)N(2))] (M = Y (1), La (2)). The analogous compounds with 1,10-phenanthroline, [MCl(2)(Tp(Me2))(C(12)H(8)N(2))] (M = Y (3), La (4)), have been obtained by a similar procedure. The solid-state structures of 2-4 were determined by single-crystal X-ray diffraction and revealed that the compounds are all seven-coordinate with capped octahedral geometry. In contrast, reaction of yttrium trichloride with 1 equiv of sodium hydrotris(3,5-dimethylpyrazolyl)borate in the presence of 1 equiv of neocuproine affords [YCl(3)(Tp(Me2))][Na(neoc)(3))] (5). Compounds 1 and 2 provide an entry for the synthesis of complexes containing the bipyridyl ligand in a radical anionic form or in a dianionic form. Reaction of 1 and 2 with an excess of sodium amalgam gives [Y(Tp(Me2))(bipy)(THF)(2)] (6) and [La(Tp(Me2))(2)(bipy)] (7), respectively. The structures of both compounds have been determined by X-ray crystallography. Compound 7 can be oxidized with iodine to give [La(Tp(Me2))(2)(bipy)]I (8).