Tetramethylethylenediamine (TMEDA or TEMED) is a chemical compound with the formula (CH3)2NCH2CH2N(CH3)2. This species is derived from ethylenediamine by replacement of the four aminehydrogens with four methyl groups. It is a colorless liquid, although old samples often appear yellow. Its odor is similar to that of rotting fish.[4]
TMEDA is widely employed as a ligand for metal ions. It forms stable complexes with many metal halides, e.g. zinc chloride and copper(I) iodide, giving complexes that are soluble in organic solvents. In such complexes, TMEDA serves as a bidentate ligand.
TMEDA has an affinity for lithium ions.[4] When mixed with n-butyllithium, TMEDA's nitrogen atoms coordinate to the lithium, forming a cluster of higher reactivity than the tetramer or hexamer that n-butyllithium normally adopts. BuLi/TMEDA is able to metallate or even doubly metallate many substrates including benzene, furan, thiophene, N-alkylpyrroles, and ferrocene.[4] Many anionic organometallic complexes have been isolated as their [Li(tmeda)2]+ complexes.[5] In such complexes [Li(tmeda)2]+ behaves like a quaternary ammonium salt, such as [NEt4]+.
sec-Butyllithium/TMEDA is a useful combination in organic synthesis where the n-butyl analogue adds to substrate. TMEDA is still capable of forming a metal complex with Li in this case as mentioned above.
Other usesedit
The complexes (TMEDA)Ni(CH3)2 and [(TMEDA)Ni(o-tolyl)Cl] illustrate the use of tmeda to stabilize homogeneous catalysts.[7][8]
Synthesis of [(TMEDA)Ni(o-tolyl)Cl]
Isomersedit
Tetramethylethylenediamine can also refer to 2,3-dimethyl-2,3-diaminobutane, H2NCMe2−CMe2NH2.[9]
Referencesedit
^"N,N,N′,N′-tetramethylethylenediamine – Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Retrieved 30 June 2012.
^ abcHaynes, R. K.; Vonwiller, S. C.; Luderer, M. R. (2006). "N,N,N′,N′-Tetramethylethylenediamine". In Paquette, L. (ed.). N,N,N′,N′-Tetramethylethylenediamine. Encyclopedia of Reagents for Organic Synthesis. New York: J. Wiley & Sons. doi:10.1002/047084289X.rt064.pub2. ISBN0471936235.
^Morse, P. M.; Girolami, G. S. (1989). "Are d0 ML6 Complexes Always Octahedral? The X-ray Structure of Trigonal Prismatic [Li(tmed)]2[ZrMe6]". Journal of the American Chemical Society. 111 (11): 4114–4116. doi:10.1021/ja00193a061.
^Henderson, K. W.; Dorigo, A. E.; Liu, Q.-L.; Williard, P. G. (1997). "Effect of Polydentate Donor Molecules on Lithium Hexamethyldisilazide Aggregation: An X-ray Crystallographic and a Combination Semiempirical PM3/Single Point ab Initio Theoretical Study". J. Am. Chem. Soc. 119 (49): 11855. doi:10.1021/ja971920t.
^Shields, Jason D.; Gray, Erin E.; Doyle, Abigail G. (2015-05-01). "A Modular, Air-Stable Nickel Precatalyst". Organic Letters. 17 (9): 2166–2169. doi:10.1021/acs.orglett.5b00766. PMC4719147. PMID 25886092.
^Magano, Javier; Monfette, Sebastien (2015-04-17). "Development of an Air-Stable, Broadly Applicable Nickel Source for Nickel-Catalyzed Cross-Coupling". ACS Catalysis. 5 (5): 3120–3123. doi:10.1021/acscatal.5b00498.
^Jackson, W.Gregory; Rahman, A.F.M.Mokhlesur; Wong, M.Anthony (2004). "Solvent Exchange, Solvent Interchange, Aquation and Isomerisation Reactions of cis- and trans-[Co(tmen)2(NCMe)2]3+ in Water, Me2SO and MeCN: Kinetics and Stereochemistry". Inorganica Chimica Acta. 357 (3): 665–676. doi:10.1016/j.ica.2003.05.010.
November 11, 2023
tetramethylethylenediamine, tmeda, temed, chemical, compound, with, formula, 2nch2ch2n, this, species, derived, from, ethylenediamine, replacement, four, amine, hydrogens, with, four, methyl, groups, colorless, liquid, although, samples, often, appear, yellow,. Tetramethylethylenediamine TMEDA or TEMED is a chemical compound with the formula CH3 2NCH2CH2N CH3 2 This species is derived from ethylenediamine by replacement of the four amine hydrogens with four methyl groups It is a colorless liquid although old samples often appear yellow Its odor is similar to that of rotting fish 4 Tetramethylethylenediamine NamesPreferred IUPAC name N N N N Tetramethylethane 1 2 diamine 1 IdentifiersCAS Number 110 18 9 Y3D model JSmol Interactive imageAbbreviations TMEDA TEMEDBeilstein Reference 1732991ChEBI CHEBI 32850 NChemSpider 7746 NECHA InfoCard 100 003 405EC Number 203 744 6Gmelin Reference 2707MeSH N N N N tetramethylethylenediaminePubChem CID 8037RTECS number KV7175000UNII K90JUB7941 YUN number 2372CompTox Dashboard EPA DTXSID5026122InChI InChI 1S C6H16N2 c1 7 2 5 6 8 3 4 h5 6H2 1 4H3 NKey KWYHDKDOAIKMQN UHFFFAOYSA N NSMILES CN C CCN C CPropertiesChemical formula C 6H 16N 2Molar mass 116 208 g mol 1Appearance Colorless liquidOdor Fishy ammoniacalDensity 0 7765 g mL 1 at 20 C Melting point 58 6 C 73 6 F 214 5 KBoiling point 121 1 C 249 9 F 394 2 KSolubility in water MiscibleAcidity pKa 8 97Basicity pKb 5 85Refractive index nD 1 4179 20 C 2 HazardsGHS labelling PictogramsSignal word DangerHazard statements H225 H302 H314 H332Precautionary statements P210 P280 P305 P351 P338 P310NFPA 704 fire diamond 241Flash point 20 C 68 F 293 K Explosive limits 0 98 9 08 Lethal dose or concentration LD LC LD50 median dose 5 39 g kg 1 dermal rabbit 268 mg kg 1 oral rat 3 Related compoundsRelated amines TriethylenetetramineRelated compounds TetraacetylethylenediamineEthylenediaminetetraacetic acidEthambutolSupplementary data pageTetramethylethylenediamine data page Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Contents 1 As a reagent in synthesis 2 Other uses 3 Isomers 4 ReferencesAs a reagent in synthesis editTMEDA is widely employed as a ligand for metal ions It forms stable complexes with many metal halides e g zinc chloride and copper I iodide giving complexes that are soluble in organic solvents In such complexes TMEDA serves as a bidentate ligand TMEDA has an affinity for lithium ions 4 When mixed with n butyllithium TMEDA s nitrogen atoms coordinate to the lithium forming a cluster of higher reactivity than the tetramer or hexamer that n butyllithium normally adopts BuLi TMEDA is able to metallate or even doubly metallate many substrates including benzene furan thiophene N alkylpyrroles and ferrocene 4 Many anionic organometallic complexes have been isolated as their Li tmeda 2 complexes 5 In such complexes Li tmeda 2 behaves like a quaternary ammonium salt such as NEt4 nbsp TMEDA adduct of lithium bis trimethylsilyl amide Notice that the diamine is a bidentate ligand 6 sec Butyllithium TMEDA is a useful combination in organic synthesis where the n butyl analogue adds to substrate TMEDA is still capable of forming a metal complex with Li in this case as mentioned above Other uses editThe complexes TMEDA Ni CH3 2 and TMEDA Ni o tolyl Cl illustrate the use of tmeda to stabilize homogeneous catalysts 7 8 nbsp Synthesis of TMEDA Ni o tolyl Cl Isomers editTetramethylethylenediamine can also refer to 2 3 dimethyl 2 3 diaminobutane H2NCMe2 CMe2NH2 9 References edit N N N N tetramethylethylenediamine Compound Summary PubChem Compound USA National Center for Biotechnology Information 16 September 2004 Retrieved 30 June 2012 Lide David R ed 2009 CRC Handbook of Chemistry and Physics 90th ed Boca Raton Florida CRC Press ISBN 978 1 4200 9084 0 MSDS PDF permanent dead link a b c Haynes R K Vonwiller S C Luderer M R 2006 N N N N Tetramethylethylenediamine In Paquette L ed N N N N Tetramethylethylenediamine Encyclopedia of Reagents for Organic Synthesis New York J Wiley amp Sons doi 10 1002 047084289X rt064 pub2 ISBN 0471936235 Morse P M Girolami G S 1989 Are d0 ML6 Complexes Always Octahedral The X ray Structure of Trigonal Prismatic Li tmed 2 ZrMe6 Journal of the American Chemical Society 111 11 4114 4116 doi 10 1021 ja00193a061 Henderson K W Dorigo A E Liu Q L Williard P G 1997 Effect of Polydentate Donor Molecules on Lithium Hexamethyldisilazide Aggregation An X ray Crystallographic and a Combination Semiempirical PM3 Single Point ab Initio Theoretical Study J Am Chem Soc 119 49 11855 doi 10 1021 ja971920t Shields Jason D Gray Erin E Doyle Abigail G 2015 05 01 A Modular Air Stable Nickel Precatalyst Organic Letters 17 9 2166 2169 doi 10 1021 acs orglett 5b00766 PMC 4719147 PMID 25886092 Magano Javier Monfette Sebastien 2015 04 17 Development of an Air Stable Broadly Applicable Nickel Source for Nickel Catalyzed Cross Coupling ACS Catalysis 5 5 3120 3123 doi 10 1021 acscatal 5b00498 Jackson W Gregory Rahman A F M Mokhlesur Wong M Anthony 2004 Solvent Exchange Solvent Interchange Aquation and Isomerisation Reactions of cis and trans Co tmen 2 NCMe 2 3 in Water Me2SO and MeCN Kinetics and Stereochemistry Inorganica Chimica Acta 357 3 665 676 doi 10 1016 j ica 2003 05 010 Retrieved from https en wikipedia org w index php title Tetramethylethylenediamine amp oldid 1170738604, wikipedia, wiki, book, books, library,
