New capping agents for oximehydrazonate clathrochelates: sterically controlled synthesis, structural characterization and intramolecular reactions

Voloshin, Yan Z.; Сташ, А. И.; Varzatskii, Оleg А.; Belsky, V. K.; Maletin, Yurii A.; Strizhakova, Nataly G.

doi:10.1016/s0020-1693(98)00286-2

Cited by 22 publications

(17 citation statements)

References 29 publications

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“…Unexpected difficulties appeared in the synthesis of the TOF derivative, viz., the [4](BF 4 ) clathrochelate. At first we attempted to obtain [4](BF 4 ) by the condensation of the [1](BF 4 ) complex with TOF in the presence of catalytic amounts of trifluoroacetic anhydride as described earlier 11 for the alkylborate and o carbonylborate oxime hydrazonate iron(II) clathrochelates.…”

Section: Resultsmentioning

confidence: 99%

“…At first we attempted to obtain [4](BF 4 ) by the condensation of the [1](BF 4 ) complex with TOF in the presence of catalytic amounts of trifluoroacetic anhydride as described earlier 11 for the alkylborate and o carbonylborate oxime hydrazonate iron(II) clathrochelates. The red orange col oration of the reaction mixture has changed to dark red, but only partial dissolution of the initial [1](BF 4 ) semi clathrochelate was observed.…”

Section: Resultsmentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9] In particular, the synthesis of the iron(II) and cobalt(II) semiclathroche lates with the apical ferrocenyl substituents has earlier been reported. The following condensation of these semi сlathrochelates with an aqueous solution of formalde hyde afforded the clathrochelates with 1,3,5 triazacyclo hexane ring as an apical substituent.…”

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Synthesis and structure of the ferrocenylboron-capped clathrochelate iron(ii) oximehydrazonates

et al. 2008

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The direct template macrocyclization of 2,3 butanedione monooxime hydrazone (HDXO) with ferrocenylboronic acid on the iron(II) ion matrix afforded the ferrocenylboron capped semi clathrochelate iron(II) oximehydrazonate. The H + ion catalyzed macrocyclization of this precursor with an excess of triethyl orthoformate gave the clathrochelate complex with syn,syn,syn orientation of the ethoxy substituents relative to the 1,3,5 triazacyclohexane ring. The complexes synthesized were characterized using elemental analysis, IR and UV-Vis spectroscopies, MALDI TOF mass spectrometry, 1 H and 13 C{ 1 H} NMR, 57 Fe Mössbauer spectroscopies, and X ray diffraction analysis.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Synthesis and structure of the ferrocenylboron-capped clathrochelate iron(ii) oximehydrazonates

et al. 2008

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“…The iron(II) mono-and bis-clathrochelates under study were obtained as described previously. [4,32,[37][38][39][40][41][42] ESI-MS were obtained on a Bruker MicrOTOF-Q spectrometer equipped with an Apollo II electrospray ionization source with an ion funnel. The instrumental parameters were .…”

Section: Methodsmentioning

confidence: 99%

ESI-MS Study of Ionization Pathways and Cation-Receptor Properties of the Iron(II) Mono- and Bis-Clathrochelates

Varzatskii¹,

Shul’ga²,

Kozłowski³

et al. 2014

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Ionization pathways of iron(II) di-and hexachloromonoclathrochelates, bis-clathrochelates and their oximehydrazonate, dimethyl-and diamine-containing macrobicyclic analogs, and the cation-receptor properties of such cage compounds towards alkali metal cations (as individual ions or their mixtures) as well as the competitive complexation in the presence of 18-crown-6 were studied by ESI-MS method. Ionization of iron(II) mono-and bis-clathrochelates under the conditions of ESI-MS experiments was found to proceed via different pathways. The macrobicyclic iron(II

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“…Earlier, we could not resolve charge transfer bands corresponding to differ ent donor centers in the UV Vis spectra of a number of boron containing clathrochelates of this type. 2 The nonequivalence of the azomethine fragments of the oximehydrazonate macrobicyclic ligands can be clearly seen in the IR spectra of their complexes, which exhibit C=N stretching bands for both the oxime (C=N-O) and hydrazone (C=N-N) groups. The IR spectra of carboranyl containing clathrochelates contain character istic bands for the B-H stretching vibrations in apical substituents (ν(B-H) ≈ 2500 cm -1 ).…”

Section: Methodsmentioning

confidence: 99%

Macrocyclization of the semiclathrochelate o-carboranylboronate and n-butylboronate iron(II) oximehydrazonates: synthesis and structure of clathrochelate products and unexpected allosteric effect of the apical substituent

et al. 2007

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The template condensation of diacetylmonooxime hydrazone (HDXO) with n butylboronic acid and dimethyl ester of o carboranyldiboronic acid on the iron(II) ion matrix afforded the [Fe(DXO) 3 (ВBu)](BF 4 ) and [Fe(DXO) 3 (Вo carb)](BF 4 ) semiclathrochelates. The Н + ion catalyzed macrocyclization of these precursors with an excess of formaldehyde and triethyl orthoformate (TOF) resulted in the corresponding macrobicyclic complexes. In the case of o carboranylboronate semiclathrochelate, the macrocyclization with TOF gave the clathro chelate with the previously unknown syn,syn,anti orientation of the ethoxy substituents rela tive to the 1,3,5 triazacyclohexane capping fragment. The complexes obtained were character ized using elemental analysis, IR, UV Vis, MALDI TOF mass, 1 H, 11 B, and 13 C NMR, and 57 Fe Mössbauer spectroscopies and X ray crystallography.A number of mono and binuclear semiclathrochelate iron(II) and cobalt(II,III) tris oxime hydrazonates with bo ron , tin , antimony, and germanium containing cross linking apical groups have been obtained up to date; their Н + catalyzed condensation with triethyl orthoformate (TOF) gave in each case a sole isomer of the clathrochelate complex. In the case of boron containing clathrochelates, the ethoxy groups and the semiclathrochelate fragment are syn,syn,syn oriented with respect to the mean plane of the 1,3,5 triazacyclohexane ring, 1 whereas in the tin , antimony , and germanium containing complexes, the ethoxy groups have the anti,anti,anti orientation. 2-4 This difference was explained 5 by the change in the geometry of the semiclathrochelate precursor from trigonal pris matic (TP) for boron containing compounds to trigonal antiprismatic (TAP) for other types of cross linking groups.In this study, we planned to synthesize the binuclear clathrochelate oximehydrazonates using an о carboranyl diboronic acid derivative and to obtain previously un known n butylboronate iron(II) semiclathrochelate and to perform its macrocyclization with TOF. Results and DiscussionOnly few о carborane containing organoboron com pounds with the С-B bond, obtained by reactions of boron trichloride with appropriate С lithium derivatives, are described in the literature. 6 We synthesized methyl ester of о carboranyldiboronic acid (1) by a similar pro cedure starting from о carborane with chlorodimethoxy borane as a borylating agent (Scheme 1). According to 11 B{ 1 H} NMR spectrum of the reaction mixture, the de gree of conversion was ~75%. Apart from signals of the boron atoms of the symmetrically substituted carborane polyhedron, this spectrum contained the characteristic * Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday.

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New capping agents for oximehydrazonate clathrochelates: sterically controlled synthesis, structural characterization and intramolecular reactions

Cited by 22 publications

References 29 publications

Synthesis and structure of the ferrocenylboron-capped clathrochelate iron(ii) oximehydrazonates

Synthesis and structure of the ferrocenylboron-capped clathrochelate iron(ii) oximehydrazonates

ESI-MS Study of Ionization Pathways and Cation-Receptor Properties of the Iron(II) Mono- and Bis-Clathrochelates

Macrocyclization of the semiclathrochelate o-carboranylboronate and n-butylboronate iron(II) oximehydrazonates: synthesis and structure of clathrochelate products and unexpected allosteric effect of the apical substituent

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