Monomeric, dimeric, and trimeric calcium compounds containing substituted pyrrolyl and ketiminate ligands

Synthesis and structural characterization

Shih Mao Ho, Ching Sheng Hsiao, Amitabha Datta, Chen Hsiung Hung, Ling Chueh Chang, Ting Yu Lee, Jui-Hsien Huang

Research output: Contribution to journalArticle

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Abstract

A series of monomeric, dimeric, and trimeric calcium compounds containing substituted pyrrolyl or ketiminate ligands were synthesized, and characterized by NMR spectroscopy and single crystal X-ray diffractometry. The reaction of Ca[N(SiMe3)2]2(THF)2 with 1 equiv of [C4H3NH(2-CH2NEt2)] in toluene generates the dimeric complex, [Ca{N(SiMe3)}[μ-η1: η5-{C4H3N(2-CH2NEt 2)}]]2 (1) in which two substituted pyrrolyl ligands bind two Ca centers in a η1 and η5 fashion. The reaction between Ca[N(SiMe3)2]2(THF) 2 and 2 equiv of [C4H3NH(2-CH2NEt2)] in THF yields a monomeric calcium compound Ca[C4H 3N(2-CH2NEt2)]2(THF)2 (2) that exhibits a facial octahedral geometry on the central Ca atom. Similarly, the reactions of Ca[N(SiMe3)2]2(THF) 2 with 1 and 2 equiv of OCMeCHCMeNHAr (Ar = 2,6-diisopropylphenyl) generate [Ca(OCMeCHCMeNAr){N(SiMe3)2}]2 (3) and [Ca(μ-OCMeCHCMeNAr)-(OCMeCHCMeNAr)]2 (4), respectively. In 3, the Ca atom possesses a distorted tetrahedral geometry where as in 4, a square plane is developed by the two calcium atoms with the bridging participation of two oxygen atoms from two ketiminate ligands. The in situ reaction of OCMeCHCMeNHAr, Ca[N(SiMe3)2]2(THF)2, and isopropyl alcohol results in a trimeric calcium alkoxide compound Ca 3(μ-OCMeCHCMeNAr)2(OCMeCHCMeNAr)(μ3-O- iPr)22-O-iPr) (5). Compounds 1, 2, and 5 showed good catalytic activity in the ring-opening polymerization of ε-caprolactone and L-lactide.

Original languageEnglish
Pages (from-to)8004-8011
Number of pages8
JournalInorganic Chemistry
Volume48
Issue number16
DOIs
Publication statusPublished - 2009 Aug 17

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calcium compounds
Calcium Compounds
Ligands
Atoms
ligands
synthesis
calcium
atoms
isopropyl alcohol
2-Propanol
Geometry
Ring opening polymerization
alkoxides
Toluene
geometry
X ray diffraction analysis
Nuclear magnetic resonance spectroscopy
toluene
catalytic activity
oxygen atoms

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Cite this

Ho, Shih Mao ; Hsiao, Ching Sheng ; Datta, Amitabha ; Hung, Chen Hsiung ; Chang, Ling Chueh ; Lee, Ting Yu ; Huang, Jui-Hsien. / Monomeric, dimeric, and trimeric calcium compounds containing substituted pyrrolyl and ketiminate ligands : Synthesis and structural characterization. In: Inorganic Chemistry. 2009 ; Vol. 48, No. 16. pp. 8004-8011.
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title = "Monomeric, dimeric, and trimeric calcium compounds containing substituted pyrrolyl and ketiminate ligands: Synthesis and structural characterization",
abstract = "A series of monomeric, dimeric, and trimeric calcium compounds containing substituted pyrrolyl or ketiminate ligands were synthesized, and characterized by NMR spectroscopy and single crystal X-ray diffractometry. The reaction of Ca[N(SiMe3)2]2(THF)2 with 1 equiv of [C4H3NH(2-CH2NEt2)] in toluene generates the dimeric complex, [Ca{N(SiMe3)}[μ-η1: η5-{C4H3N(2-CH2NEt 2)}]]2 (1) in which two substituted pyrrolyl ligands bind two Ca centers in a η1 and η5 fashion. The reaction between Ca[N(SiMe3)2]2(THF) 2 and 2 equiv of [C4H3NH(2-CH2NEt2)] in THF yields a monomeric calcium compound Ca[C4H 3N(2-CH2NEt2)]2(THF)2 (2) that exhibits a facial octahedral geometry on the central Ca atom. Similarly, the reactions of Ca[N(SiMe3)2]2(THF) 2 with 1 and 2 equiv of OCMeCHCMeNHAr (Ar = 2,6-diisopropylphenyl) generate [Ca(OCMeCHCMeNAr){N(SiMe3)2}]2 (3) and [Ca(μ-OCMeCHCMeNAr)-(OCMeCHCMeNAr)]2 (4), respectively. In 3, the Ca atom possesses a distorted tetrahedral geometry where as in 4, a square plane is developed by the two calcium atoms with the bridging participation of two oxygen atoms from two ketiminate ligands. The in situ reaction of OCMeCHCMeNHAr, Ca[N(SiMe3)2]2(THF)2, and isopropyl alcohol results in a trimeric calcium alkoxide compound Ca 3(μ-OCMeCHCMeNAr)2(OCMeCHCMeNAr)(μ3-O- iPr)2(μ2-O-iPr) (5). Compounds 1, 2, and 5 showed good catalytic activity in the ring-opening polymerization of ε-caprolactone and L-lactide.",
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Monomeric, dimeric, and trimeric calcium compounds containing substituted pyrrolyl and ketiminate ligands : Synthesis and structural characterization. / Ho, Shih Mao; Hsiao, Ching Sheng; Datta, Amitabha; Hung, Chen Hsiung; Chang, Ling Chueh; Lee, Ting Yu; Huang, Jui-Hsien.

In: Inorganic Chemistry, Vol. 48, No. 16, 17.08.2009, p. 8004-8011.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Monomeric, dimeric, and trimeric calcium compounds containing substituted pyrrolyl and ketiminate ligands

T2 - Synthesis and structural characterization

AU - Ho, Shih Mao

AU - Hsiao, Ching Sheng

AU - Datta, Amitabha

AU - Hung, Chen Hsiung

AU - Chang, Ling Chueh

AU - Lee, Ting Yu

AU - Huang, Jui-Hsien

PY - 2009/8/17

Y1 - 2009/8/17

N2 - A series of monomeric, dimeric, and trimeric calcium compounds containing substituted pyrrolyl or ketiminate ligands were synthesized, and characterized by NMR spectroscopy and single crystal X-ray diffractometry. The reaction of Ca[N(SiMe3)2]2(THF)2 with 1 equiv of [C4H3NH(2-CH2NEt2)] in toluene generates the dimeric complex, [Ca{N(SiMe3)}[μ-η1: η5-{C4H3N(2-CH2NEt 2)}]]2 (1) in which two substituted pyrrolyl ligands bind two Ca centers in a η1 and η5 fashion. The reaction between Ca[N(SiMe3)2]2(THF) 2 and 2 equiv of [C4H3NH(2-CH2NEt2)] in THF yields a monomeric calcium compound Ca[C4H 3N(2-CH2NEt2)]2(THF)2 (2) that exhibits a facial octahedral geometry on the central Ca atom. Similarly, the reactions of Ca[N(SiMe3)2]2(THF) 2 with 1 and 2 equiv of OCMeCHCMeNHAr (Ar = 2,6-diisopropylphenyl) generate [Ca(OCMeCHCMeNAr){N(SiMe3)2}]2 (3) and [Ca(μ-OCMeCHCMeNAr)-(OCMeCHCMeNAr)]2 (4), respectively. In 3, the Ca atom possesses a distorted tetrahedral geometry where as in 4, a square plane is developed by the two calcium atoms with the bridging participation of two oxygen atoms from two ketiminate ligands. The in situ reaction of OCMeCHCMeNHAr, Ca[N(SiMe3)2]2(THF)2, and isopropyl alcohol results in a trimeric calcium alkoxide compound Ca 3(μ-OCMeCHCMeNAr)2(OCMeCHCMeNAr)(μ3-O- iPr)2(μ2-O-iPr) (5). Compounds 1, 2, and 5 showed good catalytic activity in the ring-opening polymerization of ε-caprolactone and L-lactide.

AB - A series of monomeric, dimeric, and trimeric calcium compounds containing substituted pyrrolyl or ketiminate ligands were synthesized, and characterized by NMR spectroscopy and single crystal X-ray diffractometry. The reaction of Ca[N(SiMe3)2]2(THF)2 with 1 equiv of [C4H3NH(2-CH2NEt2)] in toluene generates the dimeric complex, [Ca{N(SiMe3)}[μ-η1: η5-{C4H3N(2-CH2NEt 2)}]]2 (1) in which two substituted pyrrolyl ligands bind two Ca centers in a η1 and η5 fashion. The reaction between Ca[N(SiMe3)2]2(THF) 2 and 2 equiv of [C4H3NH(2-CH2NEt2)] in THF yields a monomeric calcium compound Ca[C4H 3N(2-CH2NEt2)]2(THF)2 (2) that exhibits a facial octahedral geometry on the central Ca atom. Similarly, the reactions of Ca[N(SiMe3)2]2(THF) 2 with 1 and 2 equiv of OCMeCHCMeNHAr (Ar = 2,6-diisopropylphenyl) generate [Ca(OCMeCHCMeNAr){N(SiMe3)2}]2 (3) and [Ca(μ-OCMeCHCMeNAr)-(OCMeCHCMeNAr)]2 (4), respectively. In 3, the Ca atom possesses a distorted tetrahedral geometry where as in 4, a square plane is developed by the two calcium atoms with the bridging participation of two oxygen atoms from two ketiminate ligands. The in situ reaction of OCMeCHCMeNHAr, Ca[N(SiMe3)2]2(THF)2, and isopropyl alcohol results in a trimeric calcium alkoxide compound Ca 3(μ-OCMeCHCMeNAr)2(OCMeCHCMeNAr)(μ3-O- iPr)2(μ2-O-iPr) (5). Compounds 1, 2, and 5 showed good catalytic activity in the ring-opening polymerization of ε-caprolactone and L-lactide.

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