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Cyclen
Names
Preferred IUPAC name
1,4,7,10-Tetrazacyclododecane
Other names
Tetraaza-12-crown-4
[12]aneN₄[1]
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.102.391 Edit this at Wikidata
UNII
  • InChI=1S/C8H20N4/c1-2-10-5-6-12-8-7-11-4-3-9-1/h9-12H,1-8H2 checkY
    Key: QBPPRVHXOZRESW-UHFFFAOYSA-N checkY
  • InChI=1/C8H20N4/c1-2-10-5-6-12-8-7-11-4-3-9-1/h9-12H,1-8H2
    Key: QBPPRVHXOZRESW-UHFFFAOYAQ
  • N1CCNCCNCCNCC1
  • C1CNCCNCCNCCN1
Properties
C8H20N4
Molar mass 172.276 g·mol−1
Appearance White solid
Melting point 110–113 °C (230–235 °F; 383–386 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Cyclen (1,4,7,10-tetraazacyclododecane) is an aza-crown ether with the formula (CH2CH2NH)4. It is a white solid. It forms coordination complexes with metal cations and is used to synthesize the chelating agent DOTA which has several medical applications. Being structurally simple, symmetrical, and polyfunctional, cyclen has been widely investigated.[2]

Synthesis

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Some syntheses exploit the Thorpe-Ingold effect to facilitate ring-formation. Illustrative is the reaction of the deprotonated tosylamides with ditosylates:[3]

TsN(CH2CH2NTsNa)2 + TsN(CH2CH2OTs)2 → (TsNCH2CH2)4

The resulting macrocycle can be deprotected with strong acid. Base gives the tetramine.

High dilution conditions result in a low reaction rate penalty and this disadvantage is removed in an alternative procedure starting from triethylenetetraamine and dithiooxamide to a bisamidine – also a bis(imidazoline) – followed by reduction and ring expansion with DIBAL.[4]

Cyclen synthesis dithiooxamide method

Coordination complexes

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Structure of [Ni(cyclen)(OH2)2]2+. Color code: O = red, N = blue, Ni = dark blue, white = H, gray = C.[5]

Coordination complexes of cyclen have been studied extensively.[6][7] With a 12-membered C8N4 ring, it tends to bind to four contiguous sites on octahedral metal centers, forming four 5-membered chelate rings (see figure). Cyclen also forms "bis complexes", e.g. of the type [Ln(cyclen)2]3+ where Ln = lanthanide.[8]

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  • The cyclam ligands are also tetraaza macrocycles but consist of a more flexible C10N4 ring.

References

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  1. ^ International Union of Pure and Applied Chemistry (2005). Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005). Cambridge (UK): RSC–IUPAC. ISBN 0-85404-438-8. p. 261. Electronic version.
  2. ^ Lejault, Pauline; Duskova, Katerina; Bernhard, Claire; Valverde, Ibai E.; Romieu, Anthony; Monchaud, David (2019). "The Scope of Application of Macrocyclic Polyamines Beyond Metal Chelation" (PDF). European Journal of Organic Chemistry. 2019 (36): 6146–6157. doi:10.1002/ejoc.201900870. S2CID 201220297.
  3. ^ Atkins, T. J.; Richman, J. E.; Oettle, W. F. (1978). "1,4,7,10,13,16-Hexaazacyclooctadecane". Org. Synth. 58: 86. doi:10.15227/orgsyn.058.0086.
  4. ^ Reed, David P.; Weisman, Gary R. (2002). "1,4,7,10-Tetraazacyclododecane". Org. Synth. 78: 73. doi:10.15227/orgsyn.078.0073.
  5. ^ Scott, Brian; Brewer, Karen J.; Spreer, Larry O.; Craig, Carl A.; Otvos, John W.; Calvin, Melvin; Taylor, Scott (1990). "A Novel Conformation for a Coordinated Macrocycle: The Crystal Structure of [Ni(12-aneN4)(OH2)2](CIO4)2·H2O; (12-aneN4= 1,4,7,10-Tetraazacyclododecane)". Journal of Coordination Chemistry. 21 (4): 307–313. doi:10.1080/00958979009408193.
  6. ^ Gunnlaugsson, Thorfinnur; Leonard, Joseph P. (2005). "Responsive lanthanide luminescent cyclen complexes: From switching/Sensing to supramolecular architectures". Chemical Communications (25): 3114–3131. doi:10.1039/b418196d. PMID 15968347.
  7. ^ Joshi, Tanmaya; Graham, Bim; Spiccia, Leone (2015). "Macrocyclic Metal Complexes for Metalloenzyme Mimicry and Sensor Development". Accounts of Chemical Research. 48 (8): 2366–2379. doi:10.1021/acs.accounts.5b00142. PMID 26244894.
  8. ^ Barraza, Ramiro; Sertage, Alexander G.; Kajjam, Aravind B.; Ward, Cassandra L.; Lutter, Jacob C.; Schlegel, H. Bernhard; Allen, Matthew J. (2022). "Properties of Amine-Containing Ligands That Are Necessary for Visible-Light-Promoted Catalysis with Divalent Europium". Inorganic Chemistry. 61 (49): 19649–19657. doi:10.1021/acs.inorgchem.2c02911. PMC 9771976. PMID 36417708.

Further reading

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📚 Artikel Terkait di Wikipedia

Norgestimate

Norgestimate, sold under the brand name Ortho Tri-Cyclen among others, is a progestin medication which is used in birth control pills for women and in

Birth control pill formulations

Kelnor, Barr) 250 μg norgestimate (UK: Cilest, Janssen-Cilag; US: Ortho Cyclen, Ortho-McNeil; MonoNessa, Watson; Sprintec, Barr; Sweden: Amorest) 2000 μg

DOTA (chelator)

standard suffix for chelators. DOTA is derived from the macrocycle known as cyclen. The four secondary amine groups are modified by replacement of the N-H

List of progestogens available in the United States

Mili, Mono-Linyah, Ortho Cyclen-21, Ortho Cyclen-28, Ortho Tri-Cyclen, Ortho Tri-Cyclen 21, Ortho Tri-Cyclen 28, Ortho Tri-Cyclen Lo, Previfem, Sprintec

Ethinylestradiol

Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. Ethinylestradiol is widely

There She Goes (The La's song)

used in Family Guy and the commercials for birth-control company Ortho Tri-Cyclen Lo from 2004 to 2005. The song was also used for the opening montage of

Macrocyclic ligand

complex of a thia-crown ether [Ag(18-ane-S6)]2+ Crystal structure of a Zn(II)-cyclen-ethanol dication. Fe-TAML complex. 1,4,7-Triazacyclononane is a tridentate

Cyclam

alternating five- and six-membered chelate rings. The closely related ligand cyclen ((CH2CH2NH)4) forms only five-membered C2N2M chelate rings and tends not