TY - JOUR
T1 - Coordinated 1,3-diyne diols as organometallic building blocks for large macrocycles containing oxygen and unsaturated donor units
AU - Hope-Weeks, Louisa J.
AU - Mays, Martin J.
AU - Solan, Gregory A.
PY - 2007
Y1 - 2007
N2 - The acid-catalysed reaction of [{Co2(CO)6(μ- η2-HOCH2C2-)}2] (1a) with a range of alkyl diols has been examined as means of preparing large crown-type macrocycles (up to twenty eight-membered) containing at least one coordinated 1,3-diyne unit, multiple oxygen atoms and a variety of soft donor units. Thus, interaction of la with HOCH2(CH2)nCH 2OH, allows access to the monomelic cyclised complexes [{Co 2(CO)6}2{cyclo-μ-η2:μ- η2-CH2C2C2CH2OCH 2(CH2)nCH2O}] (3a: n = 2, 3b: n = 3, 3c: n = 4) along with the dimeric cyclised species [{Co2(CO) 6}2-[cyclo-μ-η2:μ-η2- CH2C2C2CH2OCH2(CH 2)nCH2O}]2 (4a: n = 2, 4b: n = 3, 4c: n = 4). Introduction of additional oxygen donor atoms into the macrocycle can be achieved by reaction of 1a with the glycols, HO(CH2CH 2O)nH, to afford exclusively monomeric [{Co 2(CO)6}2{cyclo-μ-η2:μ- η2-CH2C2C2CH 2O(CH2-CH2O)n}] (5a: n = 3, 5b: n = 4). On the other hand, treatment of 1a with the 1,3-diyne-linked alkyl diols, HOCR2C≡CC≡ CCR2OH, furnishes the more rigid monomelic [{Co2(CO)6}2-{cyclo-μ- η2:μ-η2-CH2C2C 2CH2OCR2C2C2CR 2O}] [6a: R = H, 6b: R = Me] and dimeric macrocycles [{Co 2(CO)6}2{cyclo-μ-η2:μ- η2-CH2C2C2CH2OCR 2C2C2CR2O}]2 [7a: R = H, 7b: R = Me], whereas the use of the alkynyl- or aryl-linked alkyl diols, HOCH2(L)CH2OH, affords the unsymmetrical dimeric [{Co 2-(CO)6}2{cyclo-μ-η2:μ- η2-CH2C2C2CH2] 2O{OCH2(L)CH2O}] [8a: L = -C≡C-, 8b: L = 1,4-C6H4] and symmetrical dimeric species [{Co 2(CO)6}2{cyclo-μ-η2:μ- η2-CH2C2C2CH2OCH 2(L)-CH2O}]2 [9a: L = -C≡C- 9b: L = 1,4-C6H4]. Also isolated as a by-product from all the above reactions is the self-dimerised macrocycle [{Co2(CO) 6}2{cyclo-μ-η2:μ-η2- CH2C2C2CH2O}]2 (2) which can itself be synthesised more directly by treating la with catalytic quantities of HBF4·OEt2. Single crystal X-ray diffraction studies have been performed on 2, 3a, 5a, 7a, 8a, 8b and 9a.
AB - The acid-catalysed reaction of [{Co2(CO)6(μ- η2-HOCH2C2-)}2] (1a) with a range of alkyl diols has been examined as means of preparing large crown-type macrocycles (up to twenty eight-membered) containing at least one coordinated 1,3-diyne unit, multiple oxygen atoms and a variety of soft donor units. Thus, interaction of la with HOCH2(CH2)nCH 2OH, allows access to the monomelic cyclised complexes [{Co 2(CO)6}2{cyclo-μ-η2:μ- η2-CH2C2C2CH2OCH 2(CH2)nCH2O}] (3a: n = 2, 3b: n = 3, 3c: n = 4) along with the dimeric cyclised species [{Co2(CO) 6}2-[cyclo-μ-η2:μ-η2- CH2C2C2CH2OCH2(CH 2)nCH2O}]2 (4a: n = 2, 4b: n = 3, 4c: n = 4). Introduction of additional oxygen donor atoms into the macrocycle can be achieved by reaction of 1a with the glycols, HO(CH2CH 2O)nH, to afford exclusively monomeric [{Co 2(CO)6}2{cyclo-μ-η2:μ- η2-CH2C2C2CH 2O(CH2-CH2O)n}] (5a: n = 3, 5b: n = 4). On the other hand, treatment of 1a with the 1,3-diyne-linked alkyl diols, HOCR2C≡CC≡ CCR2OH, furnishes the more rigid monomelic [{Co2(CO)6}2-{cyclo-μ- η2:μ-η2-CH2C2C 2CH2OCR2C2C2CR 2O}] [6a: R = H, 6b: R = Me] and dimeric macrocycles [{Co 2(CO)6}2{cyclo-μ-η2:μ- η2-CH2C2C2CH2OCR 2C2C2CR2O}]2 [7a: R = H, 7b: R = Me], whereas the use of the alkynyl- or aryl-linked alkyl diols, HOCH2(L)CH2OH, affords the unsymmetrical dimeric [{Co 2-(CO)6}2{cyclo-μ-η2:μ- η2-CH2C2C2CH2] 2O{OCH2(L)CH2O}] [8a: L = -C≡C-, 8b: L = 1,4-C6H4] and symmetrical dimeric species [{Co 2(CO)6}2{cyclo-μ-η2:μ- η2-CH2C2C2CH2OCH 2(L)-CH2O}]2 [9a: L = -C≡C- 9b: L = 1,4-C6H4]. Also isolated as a by-product from all the above reactions is the self-dimerised macrocycle [{Co2(CO) 6}2{cyclo-μ-η2:μ-η2- CH2C2C2CH2O}]2 (2) which can itself be synthesised more directly by treating la with catalytic quantities of HBF4·OEt2. Single crystal X-ray diffraction studies have been performed on 2, 3a, 5a, 7a, 8a, 8b and 9a.
KW - Alkynes
KW - Cobalt complexes
KW - Macrocycles
KW - Nicholas reaction
KW - Oxygen
UR - http://www.scopus.com/inward/record.url?scp=34447526457&partnerID=8YFLogxK
U2 - 10.1002/ejic.200700113
DO - 10.1002/ejic.200700113
M3 - Article
AN - SCOPUS:34447526457
SN - 1434-1948
SP - 3101
EP - 3114
JO - European Journal of Inorganic Chemistry
JF - European Journal of Inorganic Chemistry
IS - 19
ER -