Hyperbranched poly(ferrocenylene)s containing groups 14 and 15 elements

Syntheses, optical and thermal properties, and pyrolytic transformations into nanostructured magnetoceramics

Matthias Häußler, Qunhui Sun, Kaitian Xu, Jacky W.Y. Lam, Hongchen Dong, Ben Zhong Tang

Research output: Contribution to journalReview article

46 Citations (Scopus)

Abstract

A series of hyperbranched poly(ferrocenylene)s containing elements (E) of groups 14 [E = Si (hb-1), Ge (hb-2)] and 15 [E = P (hb-3), Sb (hb-4)] are prepared in good isolation yields (up to 82 wt%) by the salt-eliminative polycoupling of dilithioferrocene with tri-(RECl 3) or tetrachlorides of the elements (ECl 4). While the polymers with no or small R groups are insoluble or partially soluble, those with long alkyl chains (R = C nH 2n+1 with n ≥ 8) are completely soluble and film forming. The polymers exhibit solution properties characteristic of hyperbranched macromolecules: e.g. hb-1(18) shows a low intrinsic viscosity ([η] = 0.02 dL/g) despite its high absolute molecular weight (M w = 5 × 10 5). Spectroscopic analyses reveal that the polymers possess rigid skeleton structures with extended conjugations, with their absorption spectra tailing into the infrared region (> 700 nm). The polymers show good thermal stability with T d up to ∼400°C and can be graphitized into iron-containing ceramics when pyrolyzed at high temperatures, with char yields up to ∼60 wt%. While calcinations of the Si-containing polymers (hb-1) at 1000°C under nitrogen give ceramics containing mostly α-Fe nanoparticles, those of Ge-(hb-2) and Sb-containing polymers (hb-4) are completely transformed into their iron-alloys. The ceramics from the P-containing polymers (hb-3) show diffraction patterns of iron phosphides. Iron silicide nanocrystals of "large" sizes are obtained when the pyrolysis of hb-1 is conducted at a high temperature of 1200°C under argon. This ceramic is highly magnetizable (M s up to ∼51 emu/g) and shows near-zero remanence and coercivity; in other words, it is an outstanding soft ferromagnet with a high magnetic susceptibility and practically nil hysteresis loss.

Original languageEnglish (US)
Pages (from-to)67-81
Number of pages15
JournalJournal of Inorganic and Organometallic Polymers
Volume15
Issue number1
DOIs
StatePublished - Mar 1 2005

Fingerprint

Polymers
Thermodynamic properties
Optical properties
Iron
Rigid structures
Remanence
Iron alloys
Argon
Tailings
Polymer solutions
Coercive force
Magnetic susceptibility
Macromolecules
Calcination
Nanocrystals
Diffraction patterns
Hysteresis
Absorption spectra
Pyrolysis
Thermodynamic stability

All Science Journal Classification (ASJC) codes

  • Polymers and Plastics
  • Materials Chemistry

Cite this

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title = "Hyperbranched poly(ferrocenylene)s containing groups 14 and 15 elements: Syntheses, optical and thermal properties, and pyrolytic transformations into nanostructured magnetoceramics",
abstract = "A series of hyperbranched poly(ferrocenylene)s containing elements (E) of groups 14 [E = Si (hb-1), Ge (hb-2)] and 15 [E = P (hb-3), Sb (hb-4)] are prepared in good isolation yields (up to 82 wt{\%}) by the salt-eliminative polycoupling of dilithioferrocene with tri-(RECl 3) or tetrachlorides of the elements (ECl 4). While the polymers with no or small R groups are insoluble or partially soluble, those with long alkyl chains (R = C nH 2n+1 with n ≥ 8) are completely soluble and film forming. The polymers exhibit solution properties characteristic of hyperbranched macromolecules: e.g. hb-1(18) shows a low intrinsic viscosity ([η] = 0.02 dL/g) despite its high absolute molecular weight (M w = 5 × 10 5). Spectroscopic analyses reveal that the polymers possess rigid skeleton structures with extended conjugations, with their absorption spectra tailing into the infrared region (> 700 nm). The polymers show good thermal stability with T d up to ∼400°C and can be graphitized into iron-containing ceramics when pyrolyzed at high temperatures, with char yields up to ∼60 wt{\%}. While calcinations of the Si-containing polymers (hb-1) at 1000°C under nitrogen give ceramics containing mostly α-Fe nanoparticles, those of Ge-(hb-2) and Sb-containing polymers (hb-4) are completely transformed into their iron-alloys. The ceramics from the P-containing polymers (hb-3) show diffraction patterns of iron phosphides. Iron silicide nanocrystals of {"}large{"} sizes are obtained when the pyrolysis of hb-1 is conducted at a high temperature of 1200°C under argon. This ceramic is highly magnetizable (M s up to ∼51 emu/g) and shows near-zero remanence and coercivity; in other words, it is an outstanding soft ferromagnet with a high magnetic susceptibility and practically nil hysteresis loss.",
author = "Matthias H{\"a}u{\ss}ler and Qunhui Sun and Kaitian Xu and Lam, {Jacky W.Y.} and Hongchen Dong and Tang, {Ben Zhong}",
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Hyperbranched poly(ferrocenylene)s containing groups 14 and 15 elements : Syntheses, optical and thermal properties, and pyrolytic transformations into nanostructured magnetoceramics. / Häußler, Matthias; Sun, Qunhui; Xu, Kaitian; Lam, Jacky W.Y.; Dong, Hongchen; Tang, Ben Zhong.

In: Journal of Inorganic and Organometallic Polymers, Vol. 15, No. 1, 01.03.2005, p. 67-81.

Research output: Contribution to journalReview article

TY - JOUR

T1 - Hyperbranched poly(ferrocenylene)s containing groups 14 and 15 elements

T2 - Syntheses, optical and thermal properties, and pyrolytic transformations into nanostructured magnetoceramics

AU - Häußler, Matthias

AU - Sun, Qunhui

AU - Xu, Kaitian

AU - Lam, Jacky W.Y.

AU - Dong, Hongchen

AU - Tang, Ben Zhong

PY - 2005/3/1

Y1 - 2005/3/1

N2 - A series of hyperbranched poly(ferrocenylene)s containing elements (E) of groups 14 [E = Si (hb-1), Ge (hb-2)] and 15 [E = P (hb-3), Sb (hb-4)] are prepared in good isolation yields (up to 82 wt%) by the salt-eliminative polycoupling of dilithioferrocene with tri-(RECl 3) or tetrachlorides of the elements (ECl 4). While the polymers with no or small R groups are insoluble or partially soluble, those with long alkyl chains (R = C nH 2n+1 with n ≥ 8) are completely soluble and film forming. The polymers exhibit solution properties characteristic of hyperbranched macromolecules: e.g. hb-1(18) shows a low intrinsic viscosity ([η] = 0.02 dL/g) despite its high absolute molecular weight (M w = 5 × 10 5). Spectroscopic analyses reveal that the polymers possess rigid skeleton structures with extended conjugations, with their absorption spectra tailing into the infrared region (> 700 nm). The polymers show good thermal stability with T d up to ∼400°C and can be graphitized into iron-containing ceramics when pyrolyzed at high temperatures, with char yields up to ∼60 wt%. While calcinations of the Si-containing polymers (hb-1) at 1000°C under nitrogen give ceramics containing mostly α-Fe nanoparticles, those of Ge-(hb-2) and Sb-containing polymers (hb-4) are completely transformed into their iron-alloys. The ceramics from the P-containing polymers (hb-3) show diffraction patterns of iron phosphides. Iron silicide nanocrystals of "large" sizes are obtained when the pyrolysis of hb-1 is conducted at a high temperature of 1200°C under argon. This ceramic is highly magnetizable (M s up to ∼51 emu/g) and shows near-zero remanence and coercivity; in other words, it is an outstanding soft ferromagnet with a high magnetic susceptibility and practically nil hysteresis loss.

AB - A series of hyperbranched poly(ferrocenylene)s containing elements (E) of groups 14 [E = Si (hb-1), Ge (hb-2)] and 15 [E = P (hb-3), Sb (hb-4)] are prepared in good isolation yields (up to 82 wt%) by the salt-eliminative polycoupling of dilithioferrocene with tri-(RECl 3) or tetrachlorides of the elements (ECl 4). While the polymers with no or small R groups are insoluble or partially soluble, those with long alkyl chains (R = C nH 2n+1 with n ≥ 8) are completely soluble and film forming. The polymers exhibit solution properties characteristic of hyperbranched macromolecules: e.g. hb-1(18) shows a low intrinsic viscosity ([η] = 0.02 dL/g) despite its high absolute molecular weight (M w = 5 × 10 5). Spectroscopic analyses reveal that the polymers possess rigid skeleton structures with extended conjugations, with their absorption spectra tailing into the infrared region (> 700 nm). The polymers show good thermal stability with T d up to ∼400°C and can be graphitized into iron-containing ceramics when pyrolyzed at high temperatures, with char yields up to ∼60 wt%. While calcinations of the Si-containing polymers (hb-1) at 1000°C under nitrogen give ceramics containing mostly α-Fe nanoparticles, those of Ge-(hb-2) and Sb-containing polymers (hb-4) are completely transformed into their iron-alloys. The ceramics from the P-containing polymers (hb-3) show diffraction patterns of iron phosphides. Iron silicide nanocrystals of "large" sizes are obtained when the pyrolysis of hb-1 is conducted at a high temperature of 1200°C under argon. This ceramic is highly magnetizable (M s up to ∼51 emu/g) and shows near-zero remanence and coercivity; in other words, it is an outstanding soft ferromagnet with a high magnetic susceptibility and practically nil hysteresis loss.

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