Fenske-Hall molecular orbitals

Its absorption spectrum shows one band at 320 nm (e = 2900 M 1cm 1), assigned to the cti - ct2 transition localized in the Au-Tl moiety. The emission spectrum in the solid state at 77 K shows a band at 602 nm, which is attributable to a transition between orbitals that appear as a result of the metal-metal interaction. In this sense, Fenske-Hall molecular orbital calculations indicate that the ground state is the result of the mixing of the empty 6s and 6pz orbitals of gold(I) with the filled 6,v and the empty 6pz orbitals of thallium(I). In frozen solution, this derivative shows a shift of the emission to 536 nm, which has been explained by a higher aggregation of [AuT1(MTP)2] units in the solid state if compared to the situation in solution. 

The absorption spectrum of the gold-lead complex shows two bands at 290 nm (e = 28598 M-1cm-1) and 385 nm (e = 7626 M-1cm-1), while the emission spectrum in the solid state shows only one band at 752 nm at room temperature. It was assigned to a transition between orbitals that appear as a result of the gold-lead interaction. Thus Fenske-Hall molecular orbital calculations indicated that the HOMO is constituted from the 6pz orbital of gold and 6s orbital of lead and the LUMO is entirely constituted from the 6pz orbitals of these atoms. 

Recently SO2, CpMn(C0)2(S02), CpMn(CO)3 and (Me5-Cp)Mn(C0)2(S02) have been examined by Lichtenberger and Campbell " using photoelectron spectroscopy and Fenske-Hall molecular orbital methods. While the results are in basic agreement with previous calculations the following additional conclusions were drawn relative to SO2 binding. 

Chapter 40 - Forty years of Fenske-Hall molecular orbital theory. Pages 1143-1165, Charles Edwin Webster and Michael B. Hall... 

Forty years of Fenske-Hall molecular orbital theory... 

The assignment that the emissions arise from a LMCT [E M4] excited state with mixing of a metal-centered d sjd p) state has been substantiated by ab initio and Fenske-Hall molecular orbital calculations performed for the silver(I) clusters. These results revealed that the HOMOs of the clusters are principally Ag—E bonding orbitals, while the LUMOs are metal-localized orbitals with predominantly 55 and 5p character. Furthermore, the calculated HOMO-LUMO energy gaps decrease in the order (13a) > (13b) > (13c), consistent with the observed trend for the emission energies of the complexes. 

Xiv,585-598 x 38,599,600 Synthesized. Fenske-Hall molecular orbital calculations... 

P(CH3)3. UV-photoelectron spectroscopy and Fenske-Hall molecular orbital calculations have been used to compare the species and its derivatives with the analogous cluster (p-H)2(CO)9-OS3CCO and its derivatives. The conclusions of the study are that when bound to a metal cluster, boron can act as pseudometal atom. Apparently the orbitals of the apical boron atom are less stable than those of an apical carbon atom and thus are in a better position to interact with high-lying metal orbitals [12]. 

Nonparametrized Fenske-Hall molecular orbital calculations on the carbyne complexes fra s-[CrX(CO)4(CR)] (X = Cl, Br, or I R = Me, Ph, or NEt2) support an earlier contention that nucleophilic additions to carbyne ligands are frontier orbital controlled rather than charge controlled. Thus, the only such complex to undergo nucleophilic addition to its carbyne carbon atom, namely, trans-[CrBr(CO)4(CC6H4Me-p)], is the only one whose LUMO corresponds to a Cr-carbyne ir-antibond. 

The results of Fenske-Hall molecular orbital calculations for transition metal thiophene complexes with the ligand bound in 1)5, T l-S-bound, 1)2,1 4 t 4-S-112 and ring-opened modes have been reported335. Formation of Ti -complexes such as [Cp Ir(Ti4-2,5-diinethylthiophene)]2+ was found to be favoured by the presence of elecron-rich metal centres and also to lead to activation of the ring with respect to a ring-opening reaction via a formal oxidative addition reaction. 

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