Picosecond investigations of the excited-state transition at 532 nm in King's complex [(C5H5)Fe(CO)]4 and synthesized analogs

Abstract

Variations of the organometallic cluster known as King's complex, [ (CsH~)Fe(C0)14, have been synthesized to study the excited-state transition responsible for reverse saturable absorption observed at 532 nm in this molecule. Picosecond pumpprobe measurements have been used to measure the excited-state cross sections and lifetimes in King's complex and the analogs methyl-King's complex, [CH3(C5H4)Fe(C0)I4, and triethylaluminum King's complex, [ (CsH5)Fe(COAl(C2H5)3)]4. Within experimental error, the excited-state parameters are unaffected by alterations to either the carbonyl or the cyclopentadienyl ligand of the King's complex. These results are consistent with an excited-state absorption resulting from a second d to d transition within the singlet states of the metal core.

Synthesis and property of BrCCH- and BrCCBr-coordinated tetrairon clusters

“…The reaction of [2](TFPB) with H-C"CMgBr in diethyl ether at room temperature gave [11](TFPB) in 95% yield, and the reaction of [2](PF 6 ) with LiS p Tol in acetonitrile at room temperature gave [12](PF 6 ) in 78% yield. These products were isolated by the appropriated methods (see Section 4) and have been characterized by elemental analysis and NMR spectroscopy (Table 1).…”

“…In the 1 H NMR spectra of [9](TFPB), [10](TFPB), and [11](TFPB), the signals of the incorporated CH 3 , CH 2 CH 3 , and C"CH groups appear at d À27.5 (CH 3 ), À37.1 (CH 2 CH 3 ) and À4.6 (CH 2 CH 3 ), and 10.31 (C"CH), respectively. The signals of the S p Tol group in [12](PF 6 ) appear at d 1.39 (SC 6 H 4 CH 3 ) 5.10, and 6.35 (SC 6 H 4 CH 3 ).…”

“…Clusters [9](BPh 4 ) and [12](PF 6 ) were further characterized by X-ray diffraction analysis. The molecular structures of the cationic parts in [9](BPh 4 ) and [12](PF 6 ) are illustrated in Figs.…”

“…The molecular structures of the cationic parts in [9](BPh 4 ) and [12](PF 6 ) are illustrated in Figs. 4 and 5, and selected interatomic distances and angles are listed in Tables 5 and 6 without the hinge metal-metal bond very similar to nonsubstituted bis(acetylene) cluster [1](TFPB), and the bond lengths and angles are also comparable to the corresponding features in [1](TFPB).…”

“…4 and 5, and selected interatomic distances and angles are listed in Tables 5 and 6 without the hinge metal-metal bond very similar to nonsubstituted bis(acetylene) cluster [1](TFPB), and the bond lengths and angles are also comparable to the corresponding features in [1](TFPB). In [9](BPh 4 ) and [12](PF 6 ), the bromine group is displaced by methyl and toluene thiolate groups, respectively. The bond distances for C4-C5 (1.534(9) Å ) and S-C3 (1.783(2) Å ) are in the normal range expected for each single bond [5].…”