Made available in DSpace on 2014-06-11T19:35:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-12-07Bitstream added on 2014-06-13T18:46:11Z : No. of bitstreams: 1 takahashi_pm_dr_araiq.pdf: 1259895 bytes, checksum: 92de4af23f7861fe3881c3842923b417 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A primeira etapa deste trabalho consistiu na síntese e caracterização espectroscópica e térmica dos complexos inéditos de níquel (II) contendo pirazóis e grupos aniônicos: [Ni(H2O)2(HPz)4](NO3)2 (1) {HPz = pirazol}, [Ni(H2O)2(HdmPz)4](NO3)2 (2) {HdmPz = 3,5- dimetilpirazol}, [NiCl2(HIPz)4].C3H6O (3) {HIPz = 4-iodopirazol}, [Ni(H2O)2(HIPz)4](NO3)2 (4), [Ni(NCS)2(HIPz)4] (5), [Ni(N3)2(HIPz)4] (6), [Ni(NCS)2(HdmIPz)4] (7) {HdmIPz = 3,5- dimetil-4-iodopirazol} e [Ni(μ-1,1-N3)(μ-1,3-N3)(HdmIPz)2]n (8) pelo método de síntese via úmida. A partir de reações no estado sólido e usando como precursores os compostos [NiCl2(HdmPz)4]n.n2H2O (9) e [Ni(NCS)2(HdmPz)4]n.n2H2O (10), foram também obtidos neste trabalho o dímero [Ni2(μ-Cl)2Cl2(HdmPz)4] (11) e o polímero de coordenação [Ni(μ-1,3-NCS)2(HdmPz)2]n (12), respectivamente. Também foi realizado um estudo sobre o comportamento vapocrômico do composto amarelo [Ni2(μ-Cl)2Cl2(HdmPz)4] (11), que na presença de vapor de água, amônia e piridina transforma-se, respectivamente, nos compostos azul claro [NiCl2(H2O)2(HdmPz)2] (11ag), lilás [Ni(NH3)4(HdmPz)2]Cl2.4H2O (11am) e azul [Ni(py)4(HdmPz)2]Cl2.H2O (11py). Estas espécies foram caracterizadas pelas técnicas de análise elementar, espectroscopia vibracional no IV e reflectância difusa na região do UV-Vis. Experimentos de susceptibilidade magnética a baixa temperatura, realizados para os compostos [Ni(H2O)2(HPz)4](NO3)2 (1), [NiCl2(HIPz)4].C3H6O (3), [Ni2(μ-Cl)2Cl2(HdmPz)4] (11), [Ni(μ-1,3-NCS)2(HdmPz)2]n (12), [Ni(NCS)2(HPz)4]n (13) e [Ni(N3)2(HPz)4]n (14), revelaram que os complexos monoméricos 1, 3, 13 e 14 não apresentaram acoplamento magnético, enquanto que os compostos 11 e 12 exibem acoplamentos antiferromagnético e ferromagnético, respectivamente. / This present work initiates with the synthesis and spectroscopic and thermal characterization of inedit nickel(II) complexes containing pyrazolyl ligands and anionic groups: [Ni(H2O)2(HPz)4](NO3)2 (1) {HPz = pyrazole}, [Ni(H2O)2(HdmPz)4](NO3)2 (2) {HdmPz = 3,5-dimethylpyrazole}, [NiCl2(HIPz)4].C3H6O (3) {HIPz = 4-iodopyrazole}, [Ni(H2O)2(HIPz)4](NO3)2 (4), [Ni(NCS)2(HIPz)4] (5), [Ni(N3)2(HIPz)4] (6), [Ni(NCS)2(HdmIPz)4] (7) {HdmIPz = 3,5-dimethyl-4-iodopyrazole} and [Ni(μ-1,1-N3)(μ-1,3-N3) (HdmIPz)2]n (8) by wet-chemical route. From reactions in the solid state and using the compounds [NiCl2(HdmPz)4]n.n2H2O (9) and [Ni(NCS)2(HdmPz)4]n.n2H2O (10) as precursor materials, the dimeric complex [Ni2(μ-Cl)2Cl2(HdmPz)4] (11) and the coordination polymer [Ni(μ-1,3-NCS)2(HdmPz)2]n (12) were obtained, respectively. Studies on vapochromic behavior of the yellow [Ni2(μ-Cl)2Cl2(HdmPz)4] (11) were also carried out in this work. This compound, when in the presence of water, ammonia or pyridine vapors becomes, respectively, in the light-blue [NiCl2(H2O)2(HdmPz)2] (11ag), purple [Ni(NH3)4(HdmPz)2]Cl2.4H2O (11am) and blue [Ni(py)4(HdmPz)2]Cl2.H2O (11py) complexes. These species were characterized by elemental analysis, infrared spectroscopy and diffuse reflectance in the UV-Vis region. Low-temperature magnetic measurements revealed that the monomeric compounds [Ni(H2O)2(HPz)4](NO3)2 (1), [NiCl2(HIPz)4].C3H6O (3), [Ni(NCS)2(HPz)4]n (13) and [Ni(N3)2(HPz)4]n (14) did not show magnetic exchange interaction while the dimmer [Ni2(μ-Cl)2Cl2(HdmPz)4] (11) and the coordination polymer [Ni(μ-1,3-NCS)2(HdmPz)2]n (12) are antiferromagnetically and ferromagnetically coupled, respectively.

Resumo: O presente trabalho contemplou a síntese e a caracterização espectroscópica de complexos pirazólicos de rutênio(II), usando como precursores o composto [RuCl2(DMSO)4] ou o sal de rutênio RuCl3.3H2O, dependendo do caso. Foram obtidas três séries de compostos inéditos: a primeira, contendo ligantes pirazólicos monodentados, de fórmula geral [RuCl2(DMSO)2L2] {L = HPz (A2), HdmPz (A3), HIdmPz (A4)}; a segunda série envolveu o uso do ligante pirazólico bidentado 3-(2'- piridil)pirazol, e pode ser representada por [RuX2(py-pzH)2].H2O {X = Cl (B1), NCS (B2)}; o terceiro conjunto de compostos apresenta o ligante 3,5-dicarboxipirazol (H3pzdc) e possui a fórmula geral [RuCl2(H3pzdc)2(L)].xH2O {L = bpy, x = 1 (C1); L = py-pzH, x = 2 (C2); L = phen, x = 2 (C3)}. Além dessas três séries de compostos foi obtido, também, o complexo [RuCl2(dcbpy)2].H2O (D1) contendo o ligante bidentado 4,4'-dicarboxi-2,2'-bipiridina (dcbpy), já conhecido da literatura. A motivação do trabalho está baseada na tentativa de utilização destes complexos pirazólicos de Ru(II) como fotossensibilizadores alternativos ao complexo de rutênio N3 (cisditiocianatobis( 2,2'-bipiridina-4,4'-ácido dicarboxílico)rutênio(II)) que vem sendo usado como sistema-modelo em células solares sensibilizadas por corante (DSSC). Por essa razão, o ligante 3,5-dicarboxipirazol (H3pzdc) foi utilizado na síntese dos compostos da série C1-C3, pois a literatura tem reportado que a presença de grupos carboxílicos no complexo, entre outros grupos de ancoragem, propicia uma adsorção adequada do corante na superfície do semicondutor. Os dados espectroscópicos (espectroscopia vibracional na região do IV, espectroscopia eletrônica e reflectância difusa na região do UV-Vis, espectroscopia de luminescência e espectroscopia de ressonância... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The principal goal of the present work was the synthesis and the spectroscopic characterization of ruthenium(II) pyrazolyl complexes, using as precursor the compound [RuCl2(DMSO)4] or the salt of ruthenium RuCl3.3H2O, depending on the case. Three inedit compounds series had been obtained: the first one, containing monodentate pyrazolyl ligands of the general formula [RuCl2(DMSO)2L2] {L = HPz (A2), HdmPz (A3), HIdmPz (A4)}; the second series involved the use of the bidentate ligand 3-(2'-pyridil)pyrazole, and can be represented by [RuX2(py-pzH)2].H2O {X = Cl (B1), NCS (B2)}; the third set of compounds contain the ligand pyrazole-3,5-dicarboxylic acid (H3pzdc) and has the general formula [RuCl2(H3pzdc)2(L)].xH2O {L = bpy, x = 1 (C1); L = py-pzH, x = 2 (C2); L = phen, x = 2 (C3)}. The complex [RuCl2(dcbpy)2].H2O (D1) containing the 4,4'-dicarboxy-2,2'- bipyridine ligand (dcbpy), already known literature, was also prepared in this work. The motivation of this research is based on the attempt of use these Ru(II) pyrazolyl complexes as alternative photosensitizers to the complex of ruthenium N3 (cisdithiocyanatebis( 4,4'-dicarboxy-2,2'-bipyridine)ruthenium(II)) that it has been used as prototipe in dye sensitized solar cells (DSSC). For this reason, the ligand pyrazole- 3,5-dicarboxylic acid (H3pzdc) was used in the synthesis of the compounds C1-C3, due to the known effective adsorption capability of anchoring groups, such as carboxylic anions, in the surface of the semiconductor. The spectroscopic data (NMR, IR, UV-Vis and Luminescence) as well the analytical results were in accordance with the proposed stoichiometric compositions for the complexes. It is important to point out that an advanced study of RMN it was realized for the complexes B2, C1 and C3, which evidenced the presence of isomers in solution. / Orientador: Regina Célia Galvão Frem Di Nardo / Coorientador: Luiz Antonio Andrade de Oliveira / Banca: Marian Rosaly Davolos / Banca: Elia Tfouni / Mestre

Scorpionates are versatile and flexible ligands with a wide range of applications including catalysis, C-H bond activation, formation of new class of materials, and mimicking enzymatic reactions. This is as a result of its steric and electronic properties, and due to the relative ease with which the 3, and 5-positions of the pyrazole ring can be functionalized. In this work, we report the synthesis of a new class of scorpionate ligands known as cyanoscorpionates which can crosslink various metal centers. Thus, bis (4-cyano-3,5-diphenylpyrazolyl)borate BpPh2,4CN was synthesized and fully characterized by 1H NMR and FT-IR. Coordination of bis (4-cyano-3,5-diphenylpyrazolyl)borate BpPh2,4CN to thallium (I) metal was performed and characterized and we are looking to elucidating its molecular structure by X-ray crystallography in future.

Resumo: A primeira etapa deste trabalho consistiu na síntese e caracterização espectroscópica e térmica dos complexos inéditos de níquel (II) contendo pirazóis e grupos aniônicos: [Ni(H2O)2(HPz)4](NO3)2 (1) {HPz = pirazol}, [Ni(H2O)2(HdmPz)4](NO3)2 (2) {HdmPz = 3,5- dimetilpirazol}, [NiCl2(HIPz)4].C3H6O (3) {HIPz = 4-iodopirazol}, [Ni(H2O)2(HIPz)4](NO3)2 (4), [Ni(NCS)2(HIPz)4] (5), [Ni(N3)2(HIPz)4] (6), [Ni(NCS)2(HdmIPz)4] (7) {HdmIPz = 3,5- dimetil-4-iodopirazol} e [Ni(μ-1,1-N3)(μ-1,3-N3)(HdmIPz)2]n (8) pelo método de síntese via úmida. A partir de reações no estado sólido e usando como precursores os compostos [NiCl2(HdmPz)4]n.n2H2O (9) e [Ni(NCS)2(HdmPz)4]n.n2H2O (10), foram também obtidos neste trabalho o dímero [Ni2(μ-Cl)2Cl2(HdmPz)4] (11) e o polímero de coordenação [Ni(μ-1,3-NCS)2(HdmPz)2]n (12), respectivamente. Também foi realizado um estudo sobre o comportamento vapocrômico do composto amarelo [Ni2(μ-Cl)2Cl2(HdmPz)4] (11), que na presença de vapor de água, amônia e piridina transforma-se, respectivamente, nos compostos azul claro [NiCl2(H2O)2(HdmPz)2] (11ag), lilás [Ni(NH3)4(HdmPz)2]Cl2.4H2O (11am) e azul [Ni(py)4(HdmPz)2]Cl2.H2O (11py). Estas espécies foram caracterizadas pelas técnicas de análise elementar, espectroscopia vibracional no IV e reflectância difusa na região do UV-Vis. Experimentos de susceptibilidade magnética a baixa temperatura, realizados para os compostos [Ni(H2O)2(HPz)4](NO3)2 (1), [NiCl2(HIPz)4].C3H6O (3), [Ni2(μ-Cl)2Cl2(HdmPz)4] (11), [Ni(μ-1,3-NCS)2(HdmPz)2]n (12), [Ni(NCS)2(HPz)4]n (13) e [Ni(N3)2(HPz)4]n (14), revelaram que os complexos monoméricos 1, 3, 13 e 14 não apresentaram acoplamento magnético, enquanto que os compostos 11 e 12 exibem acoplamentos antiferromagnético e ferromagnético, respectivamente. / Abstract: This present work initiates with the synthesis and spectroscopic and thermal characterization of inedit nickel(II) complexes containing pyrazolyl ligands and anionic groups: [Ni(H2O)2(HPz)4](NO3)2 (1) {HPz = pyrazole}, [Ni(H2O)2(HdmPz)4](NO3)2 (2) {HdmPz = 3,5-dimethylpyrazole}, [NiCl2(HIPz)4].C3H6O (3) {HIPz = 4-iodopyrazole}, [Ni(H2O)2(HIPz)4](NO3)2 (4), [Ni(NCS)2(HIPz)4] (5), [Ni(N3)2(HIPz)4] (6), [Ni(NCS)2(HdmIPz)4] (7) {HdmIPz = 3,5-dimethyl-4-iodopyrazole} and [Ni(μ-1,1-N3)(μ-1,3-N3) (HdmIPz)2]n (8) by wet-chemical route. From reactions in the solid state and using the compounds [NiCl2(HdmPz)4]n.n2H2O (9) and [Ni(NCS)2(HdmPz)4]n.n2H2O (10) as precursor materials, the dimeric complex [Ni2(μ-Cl)2Cl2(HdmPz)4] (11) and the coordination polymer [Ni(μ-1,3-NCS)2(HdmPz)2]n (12) were obtained, respectively. Studies on vapochromic behavior of the yellow [Ni2(μ-Cl)2Cl2(HdmPz)4] (11) were also carried out in this work. This compound, when in the presence of water, ammonia or pyridine vapors becomes, respectively, in the light-blue [NiCl2(H2O)2(HdmPz)2] (11ag), purple [Ni(NH3)4(HdmPz)2]Cl2.4H2O (11am) and blue [Ni(py)4(HdmPz)2]Cl2.H2O (11py) complexes. These species were characterized by elemental analysis, infrared spectroscopy and diffuse reflectance in the UV-Vis region. Low-temperature magnetic measurements revealed that the monomeric compounds [Ni(H2O)2(HPz)4](NO3)2 (1), [NiCl2(HIPz)4].C3H6O (3), [Ni(NCS)2(HPz)4]n (13) and [Ni(N3)2(HPz)4]n (14) did not show magnetic exchange interaction while the dimmer [Ni2(μ-Cl)2Cl2(HdmPz)4] (11) and the coordination polymer [Ni(μ-1,3-NCS)2(HdmPz)2]n (12) are antiferromagnetically and ferromagnetically coupled, respectively. / Orientador: Regina Célia Galvão Frem Di Nardo / Coorientador: Antonio Eduardo Mauro / Banca: Marisa Spirandeli Crespi / Banca: Eder Tadeu Gomes Cavalheiro / Banca: Clélia Mara de Paula Marques / Banca: Wendel Andrade Alves / Doutor

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Made available in DSpace on 2014-06-11T19:29:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-04-03Bitstream added on 2014-06-13T20:38:30Z : No. of bitstreams: 1 neves_tpc_me_araiq.pdf: 1261265 bytes, checksum: bf51a74eff754d073acb9af6d54b8203 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho contemplou a síntese e a caracterização espectroscópica de complexos pirazólicos de rutênio(II), usando como precursores o composto [RuCl2(DMSO)4] ou o sal de rutênio RuCl3.3H2O, dependendo do caso. Foram obtidas três séries de compostos inéditos: a primeira, contendo ligantes pirazólicos monodentados, de fórmula geral [RuCl2(DMSO)2L2] {L = HPz (A2), HdmPz (A3), HIdmPz (A4)}; a segunda série envolveu o uso do ligante pirazólico bidentado 3-(2’- piridil)pirazol, e pode ser representada por [RuX2(py-pzH)2].H2O {X = Cl (B1), NCS (B2)}; o terceiro conjunto de compostos apresenta o ligante 3,5-dicarboxipirazol (H3pzdc) e possui a fórmula geral [RuCl2(H3pzdc)2(L)].xH2O {L = bpy, x = 1 (C1); L = py-pzH, x = 2 (C2); L = phen, x = 2 (C3)}. Além dessas três séries de compostos foi obtido, também, o complexo [RuCl2(dcbpy)2].H2O (D1) contendo o ligante bidentado 4,4’-dicarboxi-2,2’-bipiridina (dcbpy), já conhecido da literatura. A motivação do trabalho está baseada na tentativa de utilização destes complexos pirazólicos de Ru(II) como fotossensibilizadores alternativos ao complexo de rutênio N3 (cisditiocianatobis( 2,2’-bipiridina-4,4’-ácido dicarboxílico)rutênio(II)) que vem sendo usado como sistema-modelo em células solares sensibilizadas por corante (DSSC). Por essa razão, o ligante 3,5-dicarboxipirazol (H3pzdc) foi utilizado na síntese dos compostos da série C1-C3, pois a literatura tem reportado que a presença de grupos carboxílicos no complexo, entre outros grupos de ancoragem, propicia uma adsorção adequada do corante na superfície do semicondutor. Os dados espectroscópicos (espectroscopia vibracional na região do IV, espectroscopia eletrônica e reflectância difusa na região do UV-Vis, espectroscopia de luminescência e espectroscopia de ressonância... / The principal goal of the present work was the synthesis and the spectroscopic characterization of ruthenium(II) pyrazolyl complexes, using as precursor the compound [RuCl2(DMSO)4] or the salt of ruthenium RuCl3.3H2O, depending on the case. Three inedit compounds series had been obtained: the first one, containing monodentate pyrazolyl ligands of the general formula [RuCl2(DMSO)2L2] {L = HPz (A2), HdmPz (A3), HIdmPz (A4)}; the second series involved the use of the bidentate ligand 3-(2'-pyridil)pyrazole, and can be represented by [RuX2(py-pzH)2].H2O {X = Cl (B1), NCS (B2)}; the third set of compounds contain the ligand pyrazole-3,5-dicarboxylic acid (H3pzdc) and has the general formula [RuCl2(H3pzdc)2(L)].xH2O {L = bpy, x = 1 (C1); L = py-pzH, x = 2 (C2); L = phen, x = 2 (C3)}. The complex [RuCl2(dcbpy)2].H2O (D1) containing the 4,4’-dicarboxy-2,2’- bipyridine ligand (dcbpy), already known literature, was also prepared in this work. The motivation of this research is based on the attempt of use these Ru(II) pyrazolyl complexes as alternative photosensitizers to the complex of ruthenium N3 (cisdithiocyanatebis( 4,4’-dicarboxy-2,2’-bipyridine)ruthenium(II)) that it has been used as prototipe in dye sensitized solar cells (DSSC). For this reason, the ligand pyrazole- 3,5-dicarboxylic acid (H3pzdc) was used in the synthesis of the compounds C1-C3, due to the known effective adsorption capability of anchoring groups, such as carboxylic anions, in the surface of the semiconductor. The spectroscopic data (NMR, IR, UV-Vis and Luminescence) as well the analytical results were in accordance with the proposed stoichiometric compositions for the complexes. It is important to point out that an advanced study of RMN it was realized for the complexes B2, C1 and C3, which evidenced the presence of isomers in solution.

A new cyanoscorpionate - tris(4-cyano-3,5-diphenylpyrazolyl)borate (TpPh2,4CN) has been synthesized and characterized. The thallium complex of this ligand TlTpPh2,4CN has also been prepared and characterized by FT-IR, 1H NMR, and single-crystal X-ray-diffraction. The complex TlTpPh2,4CN crystalized in the monoclinic space group C2/c with unit cell a = 14.6697(10) Å, b = 13.9493(10) Å, c = 19.3347(12) Å, and b= 91.761(2)°. Structural comparison of TlTpPh2,4CN with analogous complexes demonstrated the effects of both steric and electron-withdrawing substituents on coordination geometry and the electronic properties of the metal ion. There were short contacts between the cyano groups and neighboring thallium ions that also indicated the ligand’s potential to form coordination polymers.

This Thesis describes the synthesis and characterisation of new Main Group and Rare Earth alkyl, amide, alkoxide and borohydride complexes and their use as catalysts for the ring-opening polymerisation (ROP) of &epsilon;-caprolactone and rac-lactide. <strong>Chapter 1</strong> introduces ROP from an industrial and academic perspective, as well as polymer characterisation techniques. A literature review is given, with an emphasis placed on Main Group catalysts. <strong>Chapter 2</strong> describes the synthesis and characterisation of new homo- and hetero-scorpionate Main Group complexes. An introduction to homo- and hetero-scorpionate ligands is given, as well as a discussion of the ε-caprolactone and rac-lactide ROP activity displayed by the new complexes. <strong>Chapter 3</strong> describes the synthesis and characterisation of new neutral and cationic Main Group borohydride complexes supported by the tris(pyrazolyl)methane and tris(pyrazolyl)hydroborate ligands. A review of borohydride complexes is also given. The ε-caprolactone and rac-lactide ROP activity shown by the complexes presented is also discussed. <strong>Chapter 4</strong> describes the synthesis and characterisation of new mono- and di-cationic yttrium complexes supported by the tris(pyrazolyl)methane and triazacyclononane ligands. An introduction to the synthesis of neutral and cationic Rare Earth complexes is given. An overview of immortal ROP is also provided. The activity of the new complexes towards the immortal ROP of rac-lactide is also discussed. <strong>Chapter 5</strong> contains experimental details and characterising data for the new complexes reported in this thesis. CD Appendix</strong> contains .cif files for all of the new crystallographically characterised complexes.

The synthesis and reactions of hydrotris(pyrazolyl)borate, (TpR,R) supported ytterbium(II) borohydride and lanthanide(III) dialkyl (Ln = Yb, Lu) complexes were investigated. The lanthanide(III) dialkyl complexes were found to undergo both hydrogenolysis reaction and protonolysis reaction with terminal alkynes. Reaction of [(TptBu,Me)YbH]2 (1) with NH3BH3 and (TptBu,Me)YbI(THF) (2) with NaBH4 afforded the corresponding mono-ligand complexes, (TptBu,Me)Yb(BH4) (3) and (TptBu,Me)Yb(BH4)(THF) (4), respectively. Compounds 3 and 4 represent rare examples of lanthanide(II) tetrahydroborate complexes. IR spectroscopy data, in the B-H stretching region are consistent with the 3-BH4 bonding mode found in the solid state of compound 4 and the corresponding deuterium labelled BD4 analogue of 4 shows the expected IR isotope shifts. Mono-ligand lanthanide dialkyl complexes, (TpR,R)Ln(CH2SiMe2R)2(THF)0/1 (5-9) were synthesized from the homoleptic Ln(CH2SiMe2R)3(THF)2 (Ln = Yb, Lu; R = Me, Ph) complexes by two alternative and complementary methods: alkyl abstraction with the thallium salts of the ligands, TlTpR,R and protonolysis using the acid form of the ligands, HTpR,R. Hydrogenolysis of the dialkyl complexes (TpMe2)Ln(CH2SiMe3)2(THF) (7a, Yb; 8a, Lu) afforded the corresponding tetranuclear hydride complexes, [(TpMe2)LnH2]4 (11, Yb; 12, Lu). Similarly, hydrogenolysis of (Tp)Yb(CH2SiMe3)2(THF) (9) afforded the hexanuclear hydride [(Tp)YbH2]6 (13). When treated with a variety of terminal alkynes, the dialkyl complexes, (TpR,Me)Ln(CH2SiMe3)2(THF) (14a, Y; 8a, Lu), gave the corresponding bis-alkynide complexes, (TpR,Me)Ln(CCR)2 (15-27). The structures of the complexes depend on the steric size of both the alkyne substituents and the substituent on position 3 of the pyrazolyl ring. Except for the bulkiest substituents, the compounds are dimeric with two asymmetric 2-alkynide bridging groups and a coupled alkynide unit bridging the two lanthanide centers via an unusual enyne bonding motif. The synthesis of Lu(CH2Ph-4-R)3(THF)3 (R = H, 28a; R = Me, 28b) was achieved by salt metathesis reactions between KCH2Ph-4-R and LuCl3. Variable temperature NMR studies in THF shows that the formation of these complexes is accompanied by a small amount of the anionic ate K[Lu(CH2PH-4-R)4(THF)n] (30) complexes, which can be prepared independently by reaction of pure Lu(CH2Ph-4-R)3(THF)3 with one equiv. of KCH2Ph-4-R. One of the coordinated THF of 28a could be removed by trituration with toluene to give Lu(CH2Ph-4-R)3(THF)2 (29a). Protonolysis reaction with HTpR,R afforded the corresponding dibenzyl complexes, (TpR,R)Ln(CH2Ph-4-R)2(THF)n (31-33). X-ray crystal structures of complex 4, the dialkyl complexes 5b, 6b, 7 and 8; dihydride complexes 11, 12 and 13; bis-alkynide complexes 15, 16, 17, 21, 22 and 24 as well as the tribenzyl compounds 28a and 29a and dibenzyl complexes 31-33 were determined. The solution behaviour, solid state structures and structural diversity of these complexes are discussed.