Amr Abd El-Aziz El-Maradny

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application/pdf博士学位論文の要旨及び審査結果の要旨 (Summary of Thesis(DR))535628 bytesothe

Amr, Abd El-Aziz El-Maradny

Tohoku University Repository (TOUR) / 東北大学機関リポジトリ

Synthesis and Reactivity of Germylene andStannylene Bridged Diiron Complexes著者 Amr Abd El-Aziz El-Maradny号 40学位授与番号 1533URL http://hdl.handle.net/10097/38445 氏名・(本籍) 学位の種類学位記番号学位授与年月日 学位授与の要件 研究科,専攻学位論文題目論文審査委員磁核嬉二 ).n鉄 県Bた鵬蹴夫 ユ難長 .㎎鬼林 二d攻慮レ、 ドa専a二4 r学eタ ラa化enス授 マM)興び 一程mよ教量錬鎗博肇 ズZ博㎡レ筋号日難獄野鶴 レー)325項研㏄() 、E学3月鋤騨匙離荻庄飛鰯鯉薦鱗薦搬雛聯 謎.麗鍵盤蟹 アA博理平学東町団錯(論文目 次 CHAPTERIGeneralIn七roduction CHAPTER豆Pho七〇reacしionofSilyliron(n)ComplexCp*Fe(CO)2SiMe3(Cp㌔η5-C5Me5)inthePresenceofp-Tolylgermane CHAPTER皿R,eversibleThermaiandPhotochemicalInterconversionbetweencisa,nd七ra,ns IsomersoftheGermylene-BridgedDiironComplexCp㌔Fe2(CO)2(μ一CO) (μ一GeP-TolH)CHAPTERIVPhotoreacLionofSilyliron(∬)ComplexesCp'Fe(CO)2SiMe3(Cp'1η5-C5H5,η5-C5Me5)withDi-p-tolylgermane(p-To1)GeH2CHAPTERVPhotoreactionofSilyliron(H)ComplexesCp1Fe(CO)2SiMe3(Cp'=η5-C5H5, η5-C5Me5)withDi一ρTolylstannane(p-Tol)2SnH2CHAPTERWSummaryandConclusion論文内容要旨 Inthisstudy,IusedprimaryandsecondarygermanesandstannanesforむhepreparationofeitherdiironcomplexeswithM-H-E3-center2-electronbonds(E=Ge,Sn)orgermylene andstannylenebridgeddiironcomplexes、Thethermalandphotochemicalisomerization between七hegeometricisomersofmonoandbis(germylene),bridgecldiironcomplexeswere alsostu〔iie(i. InChapterH,Istudiedthepho七〇cHemicalreactionofCpTe(CO)2SiMe3(Cp』η5-C5Me5)withtheprimarygermaneρTo1GeH3.Threeclassesofcomplexeswereisolatedasproducts: (1)aredmixむureoftheoεsand乙rαπsisomersofmono(germylene)一bridgeddiironcomplex 一205一{~ ll Cp * 2Fe2(CO) 2 (!1-CO) (!1-GeHp-ToD as the major product, (2) a violet mixture of the syrt-and arLti-trarts isomers of bis (germylene)-bridged diiron complex Cp'2Fe2 (CO)2 ( fl -Gep-TolH)2, and (3) an orange complex with two Fe-H-Ge 3-center 2-electron bonds Cp'2Fe2 (CO) 2 (/1-Gep-TolH2)2 as shown in eq 1. These products are markedly different from the products of the analogous reaction with p-TolSiH3. In the case of the photochemical reaction of Cp'Fe(CO) 2SiMe3 with p-To]SiH3, only the cis and trarLs isomers of mono(silylene)-bridged diiron complex Cp'2Fe2(CO)2(/1-CO) ( /1 -Gep-TolH) were isolated. Such difference in the behavior between Si and Ge in the similar reaction is attributable to the difference in the atomic size of Si and Ge, and also to the difference in the bond lengths of Fe-Si and Fe-Ge. The ratio of syn- and arLti-trar~s isomers of bis(germylene)-bridged diiron complex Cp'2 Fe2(CO) 2 (/1-Gep-TolH) 2 in the photostationary state is 61:39. The IH NMR signals of the aromatic protons of syn-and arLti-trar~s iscnTlers of Cp'2Fe2(CO) 2 (/1-Gep-TolH) 2 were found to be temperature-dependent. Such behavior apparently results from the hindered rotation of p-tolyl groups in the presence of the adjacent bulky Cp' groups. Unlike an analogous complex Cp' 2Fe2(CO) 2(!1-Get-BuH2) 2 that affords, by both thermolysis and photolysis, only one isomer of Cp'2Fe2(CO) 2 (/1-Get-BuH) 2 (syr~-cis(H)) with evolution of H2 gas, the behavior of Cp'2Fe2(OO) 2 (!t-Gep-TolH2)2 complex in thermolysis is different from that in photolysis. Thus, the photolysis of Cp * 2Fe2 (CO)2 ( /1 -Gep-TolH2)2 afforded a mixture of syrt- and ar~ti-trafLs isomers of bis(germylene)-bridged diiron complex Cp'2Fe2 (CO) 2 (!1-Gep-TolH) 2 (Scheme 1). In contrast, thermolysis of Cp'2Fe2(CO)2 ( /1 -Gep-TolH2)2 afforded the third isomer of Cp'2Fe2(CO)2(!1 -Gep-TolH)2 which adopted the syrL-cis(H) configuration (Scheme 1). Interestingly, photochemical isomlerization of Cp'2Fe2 (CO)2 ( /1 -Gep-TolH)2 was observed, where syr~-cis(H) isomer converted to a mlxture of syrL- and anti-trar~s isomers only after I min of photolysis as shown in Scheme 2. In Chapter EI, I studied the thermal and photochemical interconversion of cis and trarts isomers of Cp'2Fe2(CO) 2 (!1-CO) ( !1 -Gep-TolH) by kinetic methods (eq 2). The equilibrium constants indicate that the trar~s isomer is thermodynamically more stable than the cis isomer. Scheme 2 shows the mechanism of isomerization for both thermal and photochemical processes. The large negative entropies of activation imply participation of the solvent (benzene) in the thermal isomerization of Cp'2Fe2 (CO) 2(/1-CO)(,1-Gep-TolH). Comparing the isomerization of Cp'2Fe2(CO)2(/1-CO)(!1-Gep-TolH) with the analogous silylene complex, it was found that the A H~ values for the isomerizations of the germylene complex are lower than the analogous silylene complex. The proportion of the cis isomer in equilibrium at room temperature is larger in germylene complex (596) than in the silicon analogue (296), apparently due to the longer Fe-Ge bond compared to the Fe-Si bond that relieves the steric repultion in the cis isomer. In Chapter IV, I studied the photoreaction of Cp'Fe(CO)2SiMe3 [Cp'= n 5-C5H5(Cp) and n 5-C5Me5 (Cp')] with the secondary germane (p-ToD 2GeH2. The photochemical reaction of Cp'Fe(CO) 2SiMe3 with the secondary germane (p-ToD 2GeH2 gave only monoiron complex Cp'Fe(CO) 2GeH(p-ToD2 (eq 3). On the other hand, the photochemical reaction of CpFe(CO)2 SiMe3 with the secondary germane (p-ToD2GeH2 gave cis and trarts isomers of both Cp2 - 206 -; } ~ { ! } * :{ ~ i i { ; ! { i { ; { ~ } ~ { ; i ! 1 i { * { i Fe2(CO)2(/1-CO) f!1-Ge(p-ToD 2} and Cp2Fe2(CO)2 {/1-Ge(p-ToD2} 2 (eq 4). The interconversion of the cis and trarLs isomers of CpaFe2(CO)2 { !1 -Ge(p-Tol)2} z was found to occur photochemically, and the molar ratio between cis and trar~s isomers at the photostationary state was 85 : 15 (eq 5). In Chapter V, I studied the photochemical reaction of Cp'Fe(CO)2SiM3 [Cp'=Cp and Cp'] with secondary or tertiary stannane (p-ToD~SnH4-" (n= 2, 3). The photolysis of CpFe (CO) 2SiMe3 with (p-ToD2SnH2 gave a complex containing two Fe-H-Sn 3-center 2-electron bonds Cp2Fe2(CO)2 { Il -Sn(p-Tol)2H}2 (eq 6). This complex is considered as the first example of a complex containing Fe...H...Sn 3-center 2-electron bond and also the first example of a complex containing two 3-center 2-electron M...H...Sn bonds. This complex adopts the trar~s configuration and is stable upon heating up to 90 'C. On the other hand, Cp2Fe2(CO) 2 {m-Sn(p-ToD 2H) 2 Ioses H2 during photolysis, and the IH NMR spectrum shows the formation of cis and trans isomers of bis(stannylene)-bridged diiron complex Cp2Fe2 (CO)2 { fl -Sn(p-Tol)2}2 (eq 7). Unfortunately, this green complex is not stable enough to isolate. The bulkiness of the Cp ligand and p-tolyl groups is thought to be not enough to stabilize such a bis(stannylene)-bridged diiron complex. The photochemical reaction of Cp'Fe(CO)2SiMe3 with the secondary stannane (p-ToD2 SnH2 gave the trares isomer of bis(stannylene)-bridged diiron complex Cp'2Fe2 (CO) 2 { /1 -Sn (p-ToD2} 2, and hydrido bis(stannyDiron complex Cp'Fe(CO)H{Sn(p-ToD2H}2 (eq 8). In contrast to Cp2Fe2(CO)2 {/1-Sn(p-ToD2} 2, the combination of bulky Cp* Iigands and p-tolyl groups stabilizes the trar~s isomer of bis(stannylene)-bridged diiron complex Cp'2Fe2(CO)z { /1 -Sn(p-ToD 2} 2 . Photolysis of a benzene-d6 solution of Cp'Fe(CO)H(Sn(p-ToD2H} 2 Ieads to the formation of the trarLs-Cp'2Fe2(CO)2 {/1-Sn(p-ToD2} 2 (eq 9). Photolysis of CpFe(CO) 2SiMe3 in the presence of tertiary stannane (p-ToD 3SnH afforded bis(stannyDhydridoiron complex CpFe(CO)H{Sn(p-ToD 3} 2 (eq 10). On the basis of the coupling constant values ofIJSn-H and 2JSnMH, I suggested that Cp2Fe2(CO) 2 {!1-Sn(p-ToD 2H} 2 contains two 3-center 2-electron bonds. - 207 -i 十 !蓼 ."県〆鰯 幽ッ.十 》＼・・ ."感!眺 書ノR 徽、・-Dロ臨写 砂eP 轟G竃RR(艶麗醗伊死蝋redlY32% 醗麟弱齢翻ω ♂、 εツη,εrαηsαη麗イrαπs亙{R 魎01e意2i%or蹴91e23%H ・,繋輪葵.. ・C/eRc・R ▽堪磁腿 、欝r.甲.齢^^■(red) ん"3min翠誤爆 んη+10min 翼 血纏》Scheme1玲 0崩 菰q・-血恥 評獣〆・・動 議γ凱藍陣華 一208一(2) 鞠爵ぐ海覆 鼠(嵐窓漸Toi)賦/ cゴsε7αη3認諺 熱響、 匁㌦ 一、■軍 艦や・ 戸㌔〆鷲 託、・丁翫醗幽晦△ 死ゆ 臨・豊幡e㎜ic鵬互1y 露雛・・. パ〆お ・ぜグ乳 職/・メ癬㌍ 、E騒2 拠7㎞聖女蝋(3)R 影e＼豆㎞ G創裟鳳 ゐ。 3蝕 認. 瑠㌍ +(灘)一90 9畠「一4 4鋪 、織、 抽ナグ鼠 茜rα灘 1伽+一必%1o騰鼠炉器霧領導霧飛躍蕪楓 ア転謬℃ oc〆co醜 。誌 ε鉛22% ズ一瓢 ・eノむ・鼠 。εsR 球磨㌣罵 かαη5n%沸 し轟雇/・・ ・謬犠ジR オrαη8(4)4ヤ 4㌍鵬+、臨,試灘豊艷へ聡や却、陶～しりし 買…s鎚 @◎毎 。c取r題RR 難%(醗鎌葛窃 齢麟粥量so幽騨 一210一 '「「~ l j I ~~~ ~f ~---Si'~ O r .' ¥ ~~ i "' '~ =j'" ' ¥. . i,:~~~ ~~ Fl~¥ . "'~" F:,~f ~'~J :¥ ' O~ ~{~~~~~"~ ~~R  ~~ ~& ~/~~ l!¥ /~~f/I~;~/ ( ;))¥ R Sh CO R **~~*~~:~~* ""~~ ~~' / *_ / E Fe OC f ' O!fn R ~ ~~~~~l~¥ / CO R R ' trans j ~~icz~s __j (7) ~/ ~ (unstable gTeen mixture) =*-~~ ; { } / ~:' /~~,/¥j~~;d:&e~f¥;~ ~~~~i)/'/'r_ ,i ~ ~ ~~~~~ ' "~~;i~)/ ~~- H_ ~: ~" /C;~J~ /(~'~ /~"'¥ ~ ""~~~'~~ ' h ~; ~=#~¥ ~ ~r~'-~~~~~~~~_~~~'~~  ~==""~~' .tl~ '~" '~"' ;'~' . '- I "  /f ･･ + F~r~~"'.. OC ~l ~'~_ ~~:~/~-=~i= ~ (8) -;~~(. ~ ~= / ~ / ~'~,., "~:~~f~ SnH~ / ~i ,._, ~P~~:~_ OC OC f nH~:~ OC 7 ~ 2~(~~/' (gree~~ R R 1 7% {gr~entsh yellew) i ~.~ ~~;.r2f'  ~..i~- ~ /f ¥F~~ H /¥. oc ~n=H_ I~ R ~ i?'v ~~ ~~'~¥ F~f~'ir~l:~~3 ~~~ oc/ j oc ~ ~in + ~3S~H ( ~. * p'"~-'o~~ ~ /~"~i'_F~~"~ :'i;::'S!" fCo (9) /InR 'e / f oc R *, i~~,v 90 ~in -=~~~* ~~~:. ~~:d/¥ ;~R ~~~~r H f ~ ~, ~!:~ (lo) R/~ ~~R OC *^*~ 43% (golden yellow) -21 1 - 論文審査の結果の要鷺 この論文は,著者が第1級または第2級ゲルマンおよびスタナンとシリル鉄錯体との光反応によって, 様々なゲルミレン及びスタニレン架橋二核錯体,およびFe-H-E3中心2電子結合(E=Ge,Sn)を持つ 二1核錯体を合成し,さらにこれら錯体の分光学的性質および反応性を調べたことについて記述したもので ある。本研究の主な成果を以下に列記する。 第1級ゲルマンp-To1GeH3の存在下でCpTe(CO)2SiMe3(Cゴ諏η5-C5Me5)に光照射すると,モノ (ゲルミレン)架橋錯体Cp*2Fe2(CO)2(μ一CO)(μ一Gep-To1H)(1)(oオs体とヵrα11s体の混合物),ビス (ゲルミレン)架橋錯体Cゴ2Fe2(CO)2(μ一Gep-TolH)2(2)(s即一乙rαπs体とα1Lδ～々α1τs体の混合物)お よびFe-H-Ge3中心一2電子結合を二つ持つ錯体Cp㌔Fe2(CO)2(μ一Gep-To1H2)2(3)(3"一〇Zs体)が 得られた。1は熱と光の両方で幾何異性化を行い,熱平衡状態ではびαπs体が,また光定常状態では。匠s体 がそれぞれ優勢となることを見出した。一方,2は熱的には異性化しないが,光照射によって異性化して, 定常状態でsyルびα1τs:α～1房乙rα几s=61:39となることがわかった。また,3は光照射しても加熱しても H2を放出してビス(ゲルミレン)錯体2を与えるが,光反応では2のsッη一翻α1τs体とαη島乙観ηs体の混合 物を与えるのに対して,熱反応(70℃)ではsッル。オs(H)体のみを与えることを見出した。同様の研究を 第2級ゲルマン(p-Tol)2GeH2およびCpFe(CO)2SiMe3(Cp=η5-C5H5)を用いて行い,シクロペンタ ジエニル配位子とゲルマンの置換基のかさ高さの関係によって生成物が様々に変化することを明らかにし た。さらに,第2級スタナン(p-To1)2SnH2とCpFe(CO)2SiMe3との光反応についても研究し,前例のな いFe-H-Sn3中心一2電子結合を二つ持つ錯体Cゴ2Fe2(CO)2(μ一Snp-To12H)2(4)を得た。4の大きな Js、H値(56Hz)は,3中心一2電子結合の存在を強く支持している。また,4は3と異なりびα几s体で あり,熱的にはH2を放出しないが,光によってH2を放出してビス(スタニレン)架橋錯体Cp2Fe2 (CO)2(μ一Snp-To12)2(5)(oεs一ぴαηs混合物,不安定)を与えることがわかった。 本論文は著者が自立して研究活動を行うに必要な高度の研究能力と学識を有していることを示している。 よって,AmrAbdEl-AzizE1-Maradny提出の論文は,博士(理学)の学位論文として合格と認める。 ～212一

Synthesis and Reactivity of Germylene and Stannylene Bridged Diiron Complexes

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ゲルミレンおよびスタニレンで架橋された鉄二核錯体の合成と反応性

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