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The coordination chemistry of sterically bulky guanidinate ligands with chromium and the lanthanide metals.

本項研究工作主要對五個結構類似的胍基配體, 即 [(2,6-Me₂C₆H₃N)C(NHPri)(NPri)]⁻ (L¹), [(2,6-Me₂C₆H₃N)C(NHCy)(NCy)]⁻ (L²), [(2,6-Me₂C₆H₃N)C{N(SiMe₃)Cy}(NCy)]⁻ (L³), [(2,6-Pri₂C₆H₃N)C{N(SiMe₃)₂}(NC₆H₃Pri₂-2,6)]⁻ (L⁴) 和 [(2,6-Pri₂C₆H₃N)C(NEt₂)(NC₆H₃Pri₂-2,6)]⁻ (L⁵) 與二價鉻以及二價鑭系金屬[Sm(II)、Eu(II) 及 Yb(II)] 的配位化學進行研究,同時,一系列由 L¹ 配體所衍生的三價鑭系金屬配合物亦成功被合成。 / 第一章概括介紹了由胍基配體所構築的金屬配合物的研究背景。 / 第二章敍述了含 L¹ 與 L⁴ 的二價鉻配合物的合成、結構及其化學反應。 通過胍基鉀化合物 [KL¹・0.5PhMe] (1) 與二氯化鉻反應可得到單核二價鉻雙胍基配合物 [Cr(L¹)₂] (3)。 通過胍基鋰化合物 [LiL⁴(Et₂O)] (2) 與二氯化鉻反應,成功製備了單胍基二價鉻配合物 [Cr(L⁴)(μ-Cl)₂Li(THF)(Et₂O)] (4)。 而把二價鉻配合物 4於甲苯溶液中重結晶可得到二聚體的二價鉻配合物 [{Cr(L⁴)(μ-Cl)}₂] (5)。 另外,我們對二價鉻配合物 3 及 4 的反應特性也進行了研究。 [Cr(L¹)₂] (3) 與單質碘、二苯基硫族化合物 PhEEPh (E = S, Se, Te) 以及叠氮金剛烷反應可得相對應的三價鉻混合配體化合物,分別爲 [Cr(L¹)₂I] (6)、[Cr(L¹)₂(EPh)] [E = S (7), Se (8), Te (9)],及四價鉻配合物 [Cr(L¹)₂{N(1-Ad)}] (10)。 透過單胍基二價鉻配合物 [Cr(L⁴)(μ-Cl)₂Li(THF)(Et₂O)] (4) 與 NaOMe反應可得甲氧基-胍基配合物 [{Cr(L⁴)(μ-OMe)}₂] (11)。 / 第三章主要報導含 L¹, L², L³ 和 L⁵ 配基的二價鑭系配合物的合成、結構和化學反應特性。 透過 [LnI₂(THF)₂] (Ln = Sm, Eu, Yb) 與胍基鉀鹽反應,我們成功合成一系列二價鑭系絡合物,包括 [{Eu(L¹)(μ-L¹)}₂] (15), [{Ln(L²)(μ-L²)}₂・nC₆H₁₄] [Ln = Eu, n = 2 (16); Ln = Yb, n = 0 (17),[Yb(L²)₂(THF)₂] (18), [Ln(L³)₂(THF)₂・0.25C₆H₁₄] [Ln = Eu (19), Yb (20)], [{Sm(L³)(μ-I)(THF)}₂] (21) 和 [Sm(L⁵)₂] (22)。 本章亦同時探討二價鑭系配合物15, 18, 20 和 22 作爲還原劑的化學反應特性。 配合物 15 與單質碘反應可得三價銪配合物 [{Eu(L¹)₂(μ-I)}₂] (23)。 配合物 18 與二苯基硫族化合物 PhEEPh (E = S, Se) 反應,可得相對應的三價鐿配合物 [{Yb(L²)₂(μ-EPh)}₂] [E = S (24), Se (25)]。 18 與氯化亞銅反應得到三價鐿配合物 [{Yb(L²)₂(μ-Cl)}₂] (26)。 除此之外,配合物 18 與偶氮苯反應得到雙核配合物 [{Yb(L²)₂}₂(μ-η²:η²-PhNNPh)] (27), 而 20 與偶氮苯的反應可得單核配合物 [Yb(L³)₂(η²-PhNNPh)・PhMe] (28)。 配合物 22 與二硫化碳的反應得出不對稱偶合配合物 [(L⁵)₂Sm(μ-η³:η²-S₂CSCS)Sm(L⁵)₂] (29)。 / 第四章敍述由胍基配體 L¹ 所衍生的一系列三價鑭系金屬配合物 [Ln(L¹)₃] [Ln = Ce (30), Pr (31), Gd (32), Tb (33), Ho (34), Er (35), Tm (36)] 的合成及其結構。 通過相對應的鑭系金屬三氯化物與 1 反應可得配合物 30-36。 另外, CeCl₃及 LuCl₃與 1 反應亦可合成 [{Ln(L¹)₂(μ-Cl)}₂] [Ln = Ce (37), Lu (38)]。 / 第五章總結了本項研究工作,並對本工作的未來發展作出建議。 / This research work is focused on the coordination chemistry of five closely related guanidinate ligands, namely [(2,6-Me₂C₆H₃N)C(NHPri)(NPri)]⁻ (L¹), [(2,6-Me₂C₆H₃N)C(NHCy)(NCy)]⁻ (L²), [(2,6Me₂C₆H₃N)C{N(SiMe₃)Cy}(NCy)]⁻ (L³), [(2,6Pri₂C₆H₃N)C{N(SiMe₃)₂}(NC₆H₃Pri₂-2,6)]⁻ (L⁴) and [(2,6-Pri₂C₆H₃N)C(NEt₂)(NC₆H₃Pri₂-2,6)]⁻ (L⁵), with divalent chromium and lanthanide metal ions. A series of trivalent lanthanide derivatives of the L¹ ligand were also prepared and structurally characterized in this work. / Chapter 1 gives a brief introduction to the chemistry of metal guanidinate complexes. / Chapter 2 reports on the synthesis, structure and reactivity of chromium(II) complexes derived from the bulky L¹ and L⁴ ligands. Treatment of CrCl₂ with [KL¹・0.5PhMe] (1) afforded the mononuclear Cr(II) bis(guanidinate) complex [Cr(L¹)₂] (3). Reaction of CrCl₂ with [LiL⁴(Et₂O)] (2) resulted in the isolation of ate-complex [Cr(L⁴)(μ-Cl)₂Li(THF)(Et₂O)] (4). Recrystallization of 4 from toluene gave neutral, dimeric [{Cr(L⁴)(μ-Cl)}₂] (5). The reaction chemistry of the Cr(II) complex 3 and 4 was studied. Treatment of 3 with I₂, PhEEPh (E = S, Se, Te), 1-AdN₃ (1-Ad = 1-adamantyl) gave the corresponding mixed-ligand Cr(III) complexes, namely [Cr(L¹)₂I] (6) and [Cr(L¹)₂(EPh)] [E = S (7), Se (8), Te (9)] and Cr(IV) complex [Cr(L¹)₂{N(1-Ad)}] (10). Besides, the reaction of 4 with NaOMe resulted in the isolation of the Cr(II) methoxide-guanidinate complex [{Cr(L⁴)(μ-OMe)}₂] (11). / Chapter 3 deals with the synthesis, structure and reactivity of lanthanide(II) complexes supported by the L¹, L², L³ and L⁵ ligands. Lanthanide(II) guanidinate complexes were prepared by the reactions of an appropriate lanthanide diiodide with the corresponding potassium guanidinate complexes [KL¹・0.5PhMe] (1), [KL²(THF)₀.₅]n (12), KL³ (13) and [KL⁵(THF)₂] (14). Reaction of EuI₂(THF)₂ with 1 gave the homoleptic complex [{Eu(L¹)(μ-L¹)}₂] (15). Metathesis reactions of LnI₂(THF)₂ (Ln = Yb, Eu) with 12 and 13 led to the isolation of [{Ln(L²)(μ-L²)}₂・nC₆H₁₄] [Ln = Eu, n = 2 (16); Ln = Yb, n = 0 (17)], [Yb(L²)₂(THF)₂] (18) and [Ln(L³)₂(THF)₂・0.25C₆H₁₄] [Ln = Eu (19), Yb (20)]. Direct reaction of SmI₂(THF)₂ with 13 yielded the iodide bridged Sm(II) complex [{Sm(L³)(μ-I)(THF)}₂] (21), whilst reaction of SmI₂(THF)₂ with 14 gave homoleptic [Sm(L⁵)₂] (22). The reaction chemistry of 15, 18, 20 and 22 as reducing agents was examined. Oxidation of 15 with I₂ afforded the Eu(III) complex [{Eu(L¹)₂(μ-I)}₂] (23). Reactions of 18 with PhEEPh (E = S, Se) gave the corresponding Yb(III) chalcogenide complexes [{Yb(L²)₂(μ-EPh)}₂] [E = S (24), Se (25)], whilst treatment of 18 with CuCl led to the isolation of [{Yb(L²)₂(μ-Cl)}₂] (26). Besides, addition of complex 18 to PhNNPh yielded binuclear [{Yb(L²)₂}₂(μ-η²:η²-PhNNPh)] (27), whereas treatment of 20 with PhNNPh resulted in the isolation of mononuclear [Yb(L³)₂(η²-PhNNPh)・PhMe] (28). Addition of CS₂ to 22 gave the unsymmetrical coupling product [(L⁵)₂Sm(μ-η³:η²S₂CSCS)Sm(L⁵)₂] (29). / Chapter 4 describes the preparation and structural characterization of lanthanide(III) complexes derived from L¹. A series of homoleptic lanthanide(III) tris(guanidinate) complexes [Ln(L¹)₃] [Ln = Ce (30), Pr (31), Gd (32), Tb (33), Ho (34), Er (35), Tm (36)] were prepared by the reactions of an appropriate LnCl₃ with three molar equivalents of 1. Treatment of CeCl₃ and LuCl₃ with two equivalents of 1 gave the corresponding chloride bridged guanidinate complexes [{Ln(L¹)₂(μ-Cl)}₂] [Ln = Ce (37), Lu (38)]. / Chapter 5 summarizes the findings of this study. A short description on the future prospect of this work will also be given. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Au, Chi Wai. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references. / Abstracts also in Chinese.

Identiferoai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_1077728
Date January 2014
ContributorsAu, Chi Wai (author.), Lee, Hung Kay (thesis advisor.), Chinese University of Hong Kong Graduate School. Division of Chemistry, (degree granting institution.)
Source SetsThe Chinese University of Hong Kong
LanguageEnglish, Chinese
Detected LanguageEnglish
TypeText, bibliography, text
Formatelectronic resource, electronic resource, remote, 1 online resource (xxi, 275 leaves) : illustrations (some color), computer, online resource
RightsUse of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

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