X-ray and density measurements on “early-late” transition metal glasses: consistency with “soft-sphere” structural models

A synthetic route for iridium porphyrin amido complexes has been established. Treatment of a THF solution of Ir(ttp)(CO)Cl (1) (ttp = 5,10,15,20-tetrakis(p-tolyl)porphyrinato dianion) with an aqueous mixture of NaOH and NaBH4, followed by 2-iodoethanol leads to the clean formation of the β-hydroxyethyl complex Ir(ttp)(C2H4OH) (2) in 92% yield. Heating a pyridine solution of complex 2 in the presence of ca. 5–10 equiv. of phthalimide (HNC8H4O2; HPhth) leads to the formation of Ir(ttp)(C5H5N)(CH2CH2Phth) (3). The replacement of pyridine by THF as the reaction solvent leads to the formation of the THF adduct Ir(ttp)(THF)(Phth) (4), which has been characterized spectroscopically. Heating a solution of 4 in pyridine leads to the formation of Ir(ttp)(C5H5N)(Phth) (5), which has been isolated in 72% yield. Complexes 3 and 5 have been characterized by X-ray crystallographic studies. Complexes 4 and 5 are rare examples of monomeric late transition metal-amido complexes and are the first examples of iridium-amido complexes featuring a porphyrin as a supporting ligand.

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Heterobimetallic early–late transition-metal tetrameric metallomacrocycles via self assembly

Chemical Communications ◽

10.1039/a604842k ◽

1997 ◽

pp. 77-78 ◽

Cited By ~ 23

Author(s):

Peter J. Stang ◽

Neal E. Persky

Keyword(s):

Transition Metal ◽

Self Assembly ◽

Late Transition Metal ◽

Late Transition ◽

Early Late

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Fragility of Metallic Glass Forming Liquids

MRS Proceedings ◽

10.1557/proc-754-cc5.9 ◽

2002 ◽

Vol 754 ◽

Cited By ~ 1

Author(s):

G. J. Fan ◽

R. K. Wunderlich ◽

H.-J. Fecht

Keyword(s):

Transition Metal ◽

Metallic Glass ◽

Liquid Structure ◽

Energy Difference ◽

Late Transition Metal ◽

Glass Forming ◽

Metal Type ◽

Gibbs Free Energy Difference ◽

Late Transition ◽

Early Late

ABSTRACTBased on the available kinetic and thermodynamic data, we compare the kinetic fragility and thermodynamic fragility of different metallic glass forming liquids. The results indicate a correlation between the kinetic and thermodynamic fragility in metallic glass forming liquids, consistent with the energy landscape model which predicts a connection between the kinetic and thermodynamic properties of supercooled liquids. The metal - metalloid glass forming alloys such as PdNiCuP are found to exhibit a distinctively different correlation as compared to early – late transition metal – type metallic glass forming alloys such as ZrTiCuNiBe. For the same thermodynamic fragility the former exhibit a much larger kinetic fragility indicating that the two classes of alloys have a different liquid structure. In addition, the relationship between the kinetic fragility and the Gibbs free energy difference between the undercooled liquid and the crystalline phases has been discussed in both metal metalloid glass forming alloys and early - late transition metal – type metallic glass forming alloys.

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