Abstract

Interaction of the commercial "Zr((OPr)-Pr-n)(4)'' with an excess of (PrOH)-Pr-i provides in high yields a new solid crystalline but highly soluble precursor Zr-2(mu-(OPr)-Pr-n)(2)((OPr)-Pr-i)(6)((PrOH)-Pr-i)(2) (2). Interaction of 1 eq. of 2 with 1 eq. of Co(acac)(2) results in quantitative transformation into a mixture of Co2Zr2((OPr)-Pr-n)(4)((OPr)-Pr-i)(6)(acac)(2) (3), with a structure representing a fragment of hexagonal packing of metal atoms and alkoxide ligands (typical for derivatives of primary alcohols), and Zr-2((OPr)-Pr-i)(6)(acac)(2) (4). Reaction of 1 eq. of homoleptic zirconium isopropoxide, Zr-2((OPr)-Pr-i)(8)((PrOH)-Pr-i)(2) (1), with 1 eq. of Co(acac)(2) provides a new complex CoZr2((OPr)-Pr-i)(8)(acac)(2) (5) having a linear chain structure (characteristic of sec-alcohol derivatives) in quantitative yield. Microhydrolysis of a mixture of 1.5 eq. of 2 and 1 eq. of Co(acac)(2) gave in moderate yield CoZr3O((OPr)-Pr-n)(3)((OPr)-Pr-i)(5)(acac)(4) (6), with a tetrahedral CoZr3O core characteristic of zirconium sec-oxoalkoxides. Modification of a solution of barium and zirconium isopropoxides in toluene (Ba:Zr=1:1) with 1.5 eq. of Hacac results almost quantitatively in a mixture of insoluble Ba(acac)(2) and soluble and volatile heterometallic alkoxide Ba2Zr4((OPr)-Pr-i)(18)(acac)(2) (7). Addition of 2 eq. of Hthd to a mixture of barium and zirconium n-propoxides in toluene (Ba:Zr=1:1) gives highly soluble and volatile complex Ba2Zr2(thd)(4)((OPr)-Pr-n)(8)((PrOH)-Pr-n)(2) (8). Reaction of the in situ obtained Ba(thd)(2) with 0.5 eq. of 2 provided almost quantitatively another highly soluble and volatile precursor Ba2Zr2(thd)(4)((OPr)-Pr-n)(2)((OPr)-Pr-i)(6) (9). Addition of 2 eq. of Hthd to a mixture of strontium and zirconium isopropoxides in toluene (Sr:Zr=1:1) gives highly soluble complex Sr2Zr2(thd)(4)((OPr)-Pr-i)(8) (10) volatilized on heating via complete decomposition into Sr(thd)(2), Zr(thd)(2)((OPr)-Pr-i)(2) and non-volatile products. Bimetallic hydroxo-isopropoxides of strontium and barium, Sr2Zr2(OH)(2)((OPr)-Pr-i)(10)((PrOH)-Pr-i)(4) (11) and Ba2Zr2(OH)(2)((OPr)-Pr-i)(10)((PrOH)-Pr-i)(6) (12), have been obtained in good yields via microhydrolysis of solutions of isopropoxides in toluene/isopropanol media. All compounds have been characterized by a variety of spectroscopic techniques, and compounds 1-9 and 11-12 also by X-ray single crystal studies. The principles in construction of zirconium alkoxides-products of thermodynamically controlled molecular self-assembly- and their stability and reactivity are discussed in connection with the sterical role played by the chosen ligands

Published in

Journal of Materials Chemistry
2004, Volume: 14, number: 21, pages: 3177-3190
Publisher: ROYAL SOC CHEMISTRY

SLU Authors

• Kessler, Vadim

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

• Seisenbaeva, Gulaim

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

• Gohil, Suresh

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

Publication identifier

DOI: https://doi.org/10.1039/b404303k

Permanent link to this page (URI)

https://res.slu.se/id/publ/3143