金屬有機化學(xué)ppt課件

1、Organometallics金屬有機化學(xué)金屬有機化學(xué)1. Introduction引論引論 1.1 Historical Development and Current Trends in Organometallic Chemistry (在金在金屬有機化學(xué)領(lǐng)域的歷史開展和當(dāng)前趨勢屬有機化學(xué)領(lǐng)域的歷史開展和當(dāng)前趨勢) 1760 The cradle(搖籃搖籃) of organometallic chemistry is a Paris military pharmacy(制制藥廠藥廠). It is there Cadet(軍校學(xué)員軍校學(xué)員) works on sympathetic i

2、nks隱顯墨水隱顯墨水based on cobalt salts. For their preparation, cobalt mineral which contain arsenic(砷砷) was used. As2O3 + 4CH3COOK - “Cadets Fuming(發(fā)煙的) liquid Contains cacodyloxide(卡可基氧) (CH3)2As2O (maldorous 惡臭的 First organometallic compound(化合物). 1827 Zeises salt NaPtCl3C2H4 First olefin(烯烴) complex(絡(luò)合

3、物、配合物) 1840 R. W. Bunsen continues the study of cacodyl compounds which he names “alkarsines. The weakness of As-As bond in molecules of the type R2As-AsR2 led to a profusion(豐富) of derivatives(衍生物) like (CH3)2AsCN whose taste is checked by Bunsen. 1849 E. Frankland, student of Bunsen, attepts the p

4、reparation of an “ethyl radical(乙基自在基). (cacodyl as well was taken to be a radical).3C2H5I + 3ZnXZnI2 + 2C2H5(C2H5)2Zn (a pyrophoric燃燒性的 liquid) C2H5ZnI(a solid) + ZnI2Frankland possesses admirable skill in the manipulation(操作) of air sensitivecompounds. As a protective atmospherehe uses hydrogen ga

5、s! 1852 Frankland prepares the important alkylmercury (烷基汞) compounds: 2CH3X + 2Na/Hg (CH3)2Hg + 2NaX Additionally: (C2H5)4Sn, (CH3)3B (1860). In the following years, alkyl transfer reactions using R2Hg and R2Zn serve in the synthesis of numerous main-group organometallics. Frankland also introduced

6、 the concept of valency(“combining power) and the term organometallic. 1852 K. J. Koning and M. E. Schweizer in Zurich first prepare (C2H5)4Pb from ethyliodide and Na/Pb alloy. In a similar manner, they also obtain (C2H5)4Sb and (C2H5)3Bi. 1859 W. Hallwachs and A. Schafarik generate alkylaluminum io

7、dides: 2Al + 3RI R2AlI + RAlI2 1863 C. Friedel and J. M. Crafts prepare Organochlorosilane: SiCl4 + m/2ZnR2 RmSiCl4-m + m/2ZnCl2 1866 J. A. Wanklyn develops a method for the synthesis of halide-free magnesium alkyls: (C2H5)2Hg + Mg (C2H5)2Mg + Hg 1868 M. P. Schutzenberger obtains Pt(CO)Cl22, first m

8、etal carbony(羰基) complex. D. I. Mendeleev uses organometallic compounds as test cases for his periodic table. Example: Know:predictedfoundSi(C2H5)4Eka-Si(C2H5)4(C. Winkler, 1887)d = 0.96d = 0.99Sn(C2H5)4bp: 160bp: 163.5 1890 L. Mond: Ni(CO)4, first binary(二元的) metal carbonyl, used in a commercial(商業(yè)

9、的) process for refining nickel. Mond is the founder of the English company ICI (Imperial Chemical Industries) as well as a renowned collector and patron(恩主) of the arts. 1899 P. Barbier replaces Mg for Zn in reactions with alkyl iodides:CH3CH3CCHH2CCOCH31. CH3I, Mg2. H2OCH3CH3CCHH2CCOHCH3CH3 Explore

10、d in more detail by Barbiers student V. Grignard (Nobel prize 1912 shared with P. Sabatier. Although less sensitive than ZnR2, RMgX is more potent(強有力的) alkyl group transfer reagent. 1901 L. F. S. Kipping prepares (C6H5)2SiO, suspects its high molecularity, and calls the material diphenylsilicone. 1

11、909 W. J. Pope: formation of (CH3)3PtI, first s-organotransition-metal compound. 1909 P. Ehrlich (inventer of chemotherapy化學(xué)療法, Nobel prize 1908) introduces Salvarsan(灑爾佛散) for the treatment of syphilis(梅毒).O2NHOAsO(OH)2Na2S2O4H2OO2NHOAsn nn = 5, 6, 7 Salvarsan 1917 W. Schlenk: Lithium alkyls via (經(jīng)

12、過) transalkylation(烷基轉(zhuǎn)移). 2Li + R2Hg 2LiR + Hg 2EtLi + Me2Hg 2MeLi + Et2Hg 1919 F. Hein from CrCl3 and PhMgBr synthesizes polyphenylchromium compounds, now known to be sandwich(三明治) complexes. 1922 T. Midgley and T. A. Boyd introduces Pb(C2H5)4 as an antiknock additive in gasoline. 1928 W. Hieber in

13、augurates(開場) his systematic study of metal carbonyls: Fe(CO)5 + H2NCH2CH2NH2 (H2NCH2CH2NH2)Fe(CO)3 + 2CO Fe(CO)5 + X2 Fe(CO)4X2 + CO 1929 F. A. Paneth generates alkyl radicals through PbR4 pyrolysis(熱解), radical identification by means of their ability to cause the transport of a metallic mirror. P

14、aneth thus reaches a goal set by Frankland in 1849. 1930 K. Ziegler encourages more extensive use of organolithium compounds in synthesis by developing a simpler way of preparation. PhCH2OMe + 2Li PhCH2Li + MeOLi (ether cleavage) H. Gilman: RX + 2Li RLi + LiX (procedure used today) 1931 W. Hieber pr

15、epares Fe(CO)4H2, first transition-metal hydride(負氫離子) complex. 1938 O. Roelen discovers hydroformylation (加氫甲?；?、羰基化)(the oxo process).CH2=CH2 + CO + H2Co2(CO)890-150 100-400 barCH3CH2COH 1939 W. Reppe starts work on the transition-metal catalyzed reactions of acetylene(乙炔).HCCH4Ni(CN)2/CaC2/THF80-1

16、20, 15 bar70% 1943 E. G. Rochow: Cu-Cat.,300 2CH3Cl + Si - (CH3)2SiCl2 + This “direct synthesis triggers large scale production and use of silicones. Preliminary work by R. Muller (Radebeul near Dresden) was interrupted by the Second World War. 1951 P. Pauson (GB) and S. A. Miller (USA) obtain ferro

17、cene(二茂鐵) (C5H5)2Fe, first sandwich complex. 1953 G. Wittig discovers the reaction reaction bearing his name.OCPhPhPh3PCH2+OPPh3+ H2CCPhPh(CO)5W=CPhPh+Ph3P=CH2(CO)5WPPh3+ H2C=CPhPh 1955 E. O. Fischer: rational synthesis of bis(benzene)chromium (C6H6)2Cr. 1955 K. Ziegler, G. Natta: polyolefins(聚烯烴) f

18、rom ethylene and propylene, respectively, in a low pressure process employing mixed metal catalysts (transition-metal halide/ AlR3). 1956 H. C. Brown: hydroborane(氫硅烷). 1959 J. Smodt, W. Hafner: preparation of (C3H5)PdCl2, installation(建立) of the field of p-allyl transition-metal complexes. 1959 R.

19、Crigee stabilization(穩(wěn)定) of cyclobutadiene(環(huán)丁二烯) by complexation in (C4Me4)NiCl22 veryfying a prediction by H. C. Longuet-Higgins and L. Orgel (1956)。 1960 M. F. Hawthorne: carboranes(碳硅烷). 1961 L. Vaska: (PPh3)2Ir(CO)Cl reversibly(可逆地) binds O2. 1963 Nobel prize to K. Ziegler and G. Natta. 1964 E.

20、O. Fischer: (CO)5WC(OMe)Me, first carbene(卡賓) complex. 1965 G. Wilkinson, R. S. Coffey: (PPh3)3RhCl acts as a homogeneous(均相的) catalyst in the hydrogenation of alkenes(烯烴). 1968 A. Streitwieser: preparation of uranocene(二茂鈾), (C8H8)2U. 1969 P. L. Timms: synthesis of organotransition-metal complexes

21、by means of metal-atom ligand(配體)-vapor cocondensation(共縮合). 1970 G. Wilkinson: kinetically inert transition-metal alkyls through blockage(阻斷) of b-elemination(消除). 1972 H. Werner: (C5H3)3Ni2+, first triple-decker(三層) sandwich complex. 1973 E. O. Fischer ICO4CrCR, first carbyne(卡拜) complex. 1973 Nob

22、el prize to E. O. Fischer and G Wilkinson. 1976 Nobel prize to W. N. Lipscomb: theoretical and experimental clarification of structure and bonding in boranes. 1979 Nobel prize to H. C. Brown and G. Wittig: application of organoboranes and methylenephosporanes, respectively, in organic synthesis. 198

23、1 R. West (1,3,5-Me3C6H2)4Si2, first stable compound with =Si=Si= double bond. 1981 Nobel prize to R. Hoffman and K. Fukui: semiempirical(半閱歷的) MO-concept in a unified discussion of structure and reactivity of inorganic, organic and organometallic molecules, isolobal analogies(等葉類比). 1983 R. G. Berg

24、man, W. A. G. Graham: intermolecular reactions of organotransition-metal compounds with alkanes (C-H activation) Problems: 1. What was the first organometallic compound? Who prepared it? 2. What was the first olefin complex? 3. In what year did P. Ehrlich won Nobel prize and what was his invention?

25、4. What was K. Ziegler and G. Nattas major discovery? 5. What was G. Wilkinsons discovery? 6. What did W. N. Lipscomb win Nobel prize for? 7. For what did G. Wittig win Nobel prize? 8. What were R. Hoffman and K. Fukui awarded Nobel prize for? 9. What project R. G. Bergman and W. A. G. Graham work f

26、or? 1.2 Classification of Organometallic Compounds Organometallic compounds are diffined as materials which possess direct, more or less polar bonds Md+ - Cd- between metal and carbon atoms. The designation of s-, p-, d-bondOverlapNumber of nodal planes Bond typeExample 0 s s 1 p p(CO)5Cr=CR2 2 d d+

27、BCH3R4ReReR4 1.3 Energy, Polarity and Reactivity of M-C Bond It is important to distinguish between thermodynamic(熱力學(xué)熱力學(xué)) (stable, unstable) and kinetic(動力學(xué)動力學(xué)) (inert, labile) 1.3.1 Stability of Main-group Organometallics Compared with the strengths of M-N, M-O and M-Halogen(鹵素鹵素) bond, M-C bonds m

28、ust be deemed weak. Generalizations M-C bond energies cover a wide range Compound (CH3)3B(CH3)3As (CH3)3Bi E(M-C)365229 141 kJ/molstrongmedium weak The mean bond energy E(M-C) with a main-group decreases with the increasing atomic number. Ionic binds are encountered if M is particularly electroposit

29、ive and /or the carbanion(碳負離子) is especially stable. Examples: Na+C5H5-, K+CPh3-, Na+CCR- Muticenter(多中心) bonding (“electron deficient bond) arises if the valence shell of M is less than half filled and the cation Mn+ is srongly polarizing (possesses a large charge/radius ration). Examples: (LiCH3)

30、4, Be(CH3)2n, Al(CH3)32 1.3.2 Lability of Main-group Organometallics All organometallic materials are thermodynamically unstable with respect to oxidation to Mon, H2O and CO2. Nevertheless, large differences in the ease of handling of organometallics are encountered which may be traced back to diffe

31、rences in kinetic inertness. Example:Heat of combustionThermodynamicsPropertyKineticsZn(C2H5)2-1920kJ/molunstablePyrophoric(引火的引火的)Labile(活性的活性的)Sn(CH3)4-3590kJ/molunstableairstableInert(惰性的惰性的) 1.4 Concise introduction of nomenclature in organic compounds and metal complexes (有機化合物及其金屬配合物的命名簡介) 1.4

32、.1 Nomenclature of organic compounds (有機化合物的命名)H3CCCCH3CH3HHH2-methylbutanenumber & prefixPosition & number of carbons in branchrootsuffixnumber of carbonsin backbone chaindesignatethe functional groupInternational Union of Pure and Applied Chemistry (IUPAC)國國際際純純粹粹和和應(yīng)應(yīng)用用化化學(xué)學(xué)協(xié)協(xié)會會Names for th

33、e root designating carbon numbers in the backbone chainC- numbersrootC-numbersrootOnemeth-twoeth-Threeprop-fourbut-Fivepent-sixhex-Sevenhex-eightoct-Ninenon-tendec-Elevenundec-twelvedodec-Thirteentridec-fourteentetradec-Fifteenpentadec- twentyeicos-Twenty oneheneicos- Twenty twodocos-Thirtytriacont-

34、Systematic names, common names and abbreviations for some groupsGroupsys. name com. nameabbrev.CH3-methylMeCH3CH2-ethylEtCH3(CH2)2-propylPr(CH3)2CH-1-methylethyl isopropyli-PrCH3(CH2)3-butylBu(CH3)3C-1,1-dimethylethyl- ter-butylt-BuC6H5-phenylPhC6H5CH2- phenylmethyl- benzylBezNames of common functio

35、nal groups(常見官能團的稱號常見官能團的稱號)FormulaNamePrefixSufix RHAlkanealkyl-aneRCH=CH2 Alkenevinyl-eneRCCHAlkyne-yneArHArenephenyl-benzeneRXAlkyl halidehalo-halideROHAlcoholhydroxo-olROREtheralkoxo-etherRNH2Amineamino-amineR-SHmercaptan-thiolFormulaSufixOHRAldehyde-alORRKetone-oneOOHRCarboxylic acid-oic acidOO

36、RREster-oateONH2RAmide-amideNameOrder of priority for selected functional groups (官能團的優(yōu)先順序官能團的優(yōu)先順序)Functional groupGroup prefixRank of priorityCarboxylic acid1Ester2Acid chloride3Amide4Aldehydeoxo-5Nitrilecyano-6Ketoneoxo-7Alcoholhydroxy-8Amineamino-9Etheralkoxy-10Halogenfluoro-, chloro-11bromo-, io

37、do-NO2nitro-12Some examples of nomenclature(一些命名實例一些命名實例)H3CCHH2CCH2CCH3OHO1234565-hydroxyl-3-hexanone(5- -羥羥基基- -3 3- -己己酮酮)CH3COCH2CH=COCH3CH3isopentenyl acetate (Juicy fruit gum)( (乙乙酸酸異異戊戊烯烯酯酯) )CH2COC2H3Oethyl phenylacetate (honey)(苯乙酸乙酯)H3CCOH2CObenzyl acetate (jasmine)(乙乙酸酸卞卞酯酯) 1.4.2 Nomencl

38、ature of metal complexes Order of listing ions(列出離子的順序列出離子的順序): The cation(正離子正離子) is named first, and then the anion(負離子負離子). This is the usual practice when naming a salt. NaCl Sodium Chloride Cr(NH3)6(NO3)3 hexaamminechromium(III)nitrate K2PtCl6 Potassium hexachloroplatinate(IV) Nonionic complexe

39、s: Nonionic or molecular complexes are given a one-word name. Co(NH3)3(NO2)3 Trinitrotriamminecobalt(III) Cu(CH3COCHCOCH3)2 Bis(acetylacetonato)copper(II) CH3COCH2COCH3 = acetylacetone (乙酰乙?；? Names of ligands: Neutral ligands are named as the molecule; negative ligands end o; and positive liga

40、nds (of reare occurrence) end in ium. NH2CH2CH2NH2ethylenediamine (C6H5)3Ptrphenylphosphine Cl-chloro CH3COO-acetato NH2NH3+hydrazinium(脛鎓脛鎓) NH2NH2(脛，聯(lián)氨脛，聯(lián)氨) Two exceptions to this rule are water and ammonia. H2Oaquo NH3ammine(Note the spelling with two ms; this applies only to NH3; other amines ar

41、e spelled with usual one m.) Cr(NH3)6(NO3)3 Hexaamminechromium(III)nitrate Cr(NH2CH2CH2NH2)3(NO3)3 Tris(ethylenediamine)chromium(III)nitrate Order of ligands The ligands in a complex are named in the order (1) negative, (2) neutral, and (3) positive, without separation by hyphens. Within each of the

42、se categories(范疇范疇) the groups are listed in order of increasing complexity. Pt(NH3)4(NO2)ClSO4 Chloronitrotetraammineplatinum(IV)sulfate NH4Cr(NH3)2(NCS)4 Ammonium tetrathiocyanatodiamminechromate(III) Numerical prefixes The prefixes di-, tri-, tetra-, etc., are used before such simple expressions

43、as bromo, nitro, and oxalato. Prefixes bis-, tris, tetrakis-, pentakis-, etc., are used before complex names (chiefly expressions containing the prefixes mono-, di-, tri-, etc., in the ligand name itself) such as ethylenediamine and trialkylphosphine. K3Al(C2O4)3 potassium trioxalatoaluminate(III) C

44、o(en)2Cl22SO4 dichlorobis(ethylenediamine)cobalt(III)sulfate Termination of names The ending for anionic(負離子的負離子的) complexes is ate; alternatively, -ic if named as an acid. For cationic(正離子的正離子的) and neutral complexes the name of the metal is used without any characteristic ending. Ca2Fe(CN)6 Calciu

45、m hexacyanoferate(II) Fe(H2O)6SO4 Hexaaquoiron(II)sulfate Oxidation states The oxidation state of the central atom is designated by a Roman numeral in parentheses at the end of the name of the complex, without a space between the two. For a negative oxidation state a minus sign is used before the Ro

46、man numeral, and 0 is used for zero. NaCo(CO)4 Sodium tetracarbonylcobaltate(-I) K4Ni(CN)4 Potassium tetracyanonickelate(0) Bridging groups Ligands that bridge two centers of coordination are preceded by the Greek letter m, which is repeated before the name of each different kind of bridging group.(

47、H2O)4FeOHFe(H2O)4HO(SO4)2(H3N)4CoNO2Co(NH3)4H2N(NO3)4octaaquo- -dihydroxodiiron(III)sulfateoctaammine- -amido- -nitrodicobalt(III)nitrate Point of attachment Whenever necessary, the point of attachment of a ligand is designated by placing the symbol (in italics) of the element attached after the nam

48、e of the group, with separation by hyphen. (NH4)3Cr(NCS)6 Ammonium hexathiocyanato-N-chromate(III) (NH4)2Pt(SCN)6 Ammoniu hexathiocyanato-S-platinate(IV) -SCN-, thiocyanato, -NCS-, isothiocyanato -NO2-, nitro, -ONO-, nitrito(亞硝基亞硝基) Geometrical isomers Geometrical isomers are generally named by the

49、use of the term cis to designate adjacent (90o apart) positions and trans for opposite (180o apart) positions. It is occasionally necessary to use a number system to designate the position of each ligand.PtClNO2NH3H3NRhH3NBrBrH3NNH3NH3+trans-chloronitrodiammineplatinum(II)cis-dibromotetraamminerhodi

50、um(III)ionPtClNO2BrH3NRhPyNH3BrIClNO2+1-chloro-3-nitrobromoammineplatinum(II)ion1-chloro-2-bromo-4-iodo-6-nitroamminepyridineplatinum(IV) Problems: 1.Write the formula for each of the following compounds: (1) dibromotetraammineruthenium(III)nitrate. (2)chloroaquobis(ethylenediamine) rhodium(III)chlo

51、ride. (3) calcium dioxalatodiamminecobaltate(III). (4) octaammine-m-amido-m-hydroxodicobalt(III)sulfate. (5) sodium dithiosulfato-S-argentate(I). 2. Name each of the following compounds: (1) Co(NH3)62(SO)3 (2) Co(NH3)4(NCS)ClNO3 (3) Pt(en)Cl4 (4) NH4Cr(NH3)2(NCS)4 (5) Na2K4Ni(CN)4PtH3CH2NNH2ClBr(C2O

52、4)2CoOHCo(C2O4)2HOK42. Main-Group Organometallics(主族金屬有機化合物主族金屬有機化合物) 2.1 Alkali organometallics 2.1.1 Organolithium compounds: (1) Preparation: Et2O CH3Br + 2Li CH3Li + LiBr 20 (direct synthesis) THF C5Me5H + n-BuLi C5Me5Li + n-BuH - 78 (metallation) (2) Sructure and bonding Tend to form oligmeric(

53、寡聚的) units in solution as well as in solid state. A classic example is the structure of solid methyllithium which is best described as cubic body-centered packing of (LiCH3)4 units. The latter consisting of Li4-tetrahedra with methyl groups caping the triangular faces (E. Weiss, 1964) This type of h

54、eterocubane arrangement is encounted frequently for species of constitution (AB)4. Schematic drawing of the unit (LiCH3)4LiLiLiLiCCCCHHHHHHHHHHHHLiLiLiLiCFour-center bonding molecular orbitalfrom the interaction of Li3 group orbital with a C(sp3) hybrid orbital. This 4c-MOis Li-C as well as Li-Li bo

55、ndingCH3sp3Li3 groupsp3MO diagram for oneof the four 2e4c bondsin R4Li4Dependence of degree of association of RLi on solventsLiRSolventAggregationhydrocarbonHexamer (Li6 octa.)THF, Et2OTetramer (Li4 tetra.)Me2NCH2CH2Me2monomerLi-n-C4H9cyclohexanehexamerEt2OtetramerLi-t-C4H9hydrocarbontetramerLiC6H5T

56、HF, Et2OtetramerLiCH2C6H5THF, Et2OmonomerLiC3H5(allyl)Et2OInfinite columnTHFmonomerLiLiLiPhPhPhPhPhPhPhPhOEt2OEt2OEt2In presence of chelating ligand TMEDA, phenyllithium crystalizes in dimeric structure instead of tetramer.LiLiNNNNIn the case of 1,3-(diphenyl)allyllithium, a columnar structure withb

57、ridging ( 3: 3)allyl units is realized.MeMeMeMeMeMeMeMe NMR spectroscopy of the less common nuclei Nuclei with the spin quantum number I = For small molecules, I = usually yield sharp resonance lines with half widths W1/2 (at the half height) between 1 and 10 Hz. Nuclei with spin quantum numbers I 1

58、/2 These nuclei possess electric quadrupole moments(四極矩) (deviation of the distribution of nuclear charge from spherical symmetry) which can cause extremely short nuclear relaxation time and large half widths.Magnetic properties of “unconventional” & routine nuclei NucleusN in %INucleusN in %I1H

59、99.91/251V99.87/26Li7.4157Fe2.191/27Li92.63/259Co1007/211B80.43/271Ga39.63/213C1.11/277Se7.61/219F1001/2103Rh1001/223Na1003/2119Sn8.61/225Mg10.15/2125Te7.01/227Al1003/2183W14.41/229Si4.71/2195Pt33.81/231P1001/2 (3) Reactions of organolithium compounds a) Metallation and subsquent reactions R-Li + R-

60、H R-H + R-Li With increasing CH-acidity of R-H the metallation equilibrium is shifted to the right. Consequently, the stronger CH-acid, benzene, should be amenable to high yield metallation by n-butyllithium, a salt of the weaker CH-acid, butane: C6H6 + n-C4H9Li C6H5Li + n-C4H10 Rapid Li/H exchange occurs, up