RESUMEN
The nonheme iron(IV)-oxido complex trans-N3-[(L1)FeIVîO(Cl)]+, where L1 is a derivative of the tetradentate bispidine 2,4-di(pyridine-2-yl)-3,7-diazabicyclo[3.3.1]nonane-1-one, has an S = 1 electronic ground state and is the most reactive nonheme iron model system known so far, of a similar order of reactivity as nonheme iron enzymes (C-H abstraction of cyclohexane, -90 °C (propionitrile), t1/2 = 3.5 s). The reaction with cyclohexane selectively leads to chlorocyclohexane, but "cage escape" at the [(L1)FeIII(OH)(Cl)]+/cyclohexyl radical intermediate lowers the productivity. Ligand field theory is used herein to analyze the d-d transitions of [(L1)FeIVîO(X)]n+ (X = Cl-, Br-, MeCN) in comparison with the thoroughly characterized ferryl complex of tetramethylcyclam (TMC = L2; [(L2)FeIVîO(MeCN)]2+). The ligand field parameters and d-d transition energies are shown to provide important information on the triplet-quintet gap and its correlation with oxidation reactivity.
Asunto(s)
Compuestos Férricos , Hierro , Ciclohexanos , LigandosRESUMEN
OBJECTIVES: This multicenter registry followed up patients with early-stage breast cancer treated with breast-conserving surgery and electronic brachytherapy (EBT). This report provides 1- and 2-year updates to the initial publication. METHODS: Patients were of age 50 years or more with invasive carcinoma or ductal carcinoma in situ, tumor size ≤3 cm, and negative surgical margins. After lumpectomy, patients received EBT in 10 fractions over 5 days (34 Gy total). RESULTS: Of the 69 patients enrolled, 62 were evaluated at 1 year and 20 patients at 2 years after treatment. At 1 year, 28 (45.2%) patients reported adverse events that were possibly, probably, or definitely related to treatment. Most (90%) were grade 1: manageable and typical of radiation therapy. Four events were grade 2: induration/firmness (2), field contracture (1), and seroma (1). One event was grade 3: a draining fistula at the lumpectomy site due to residual effects of a breast infection at 1 month. No recurrences have been reported. Cosmetic ratings were excellent or good in 93.4% of patients at 1 year. Most patients (69%) were energetic most or all of the time. Most patients (69% to 98%) were not affected by individual symptoms of breast disease at 1 year. Generally patients who had an adverse event did not report the corresponding symptom on the quality-of-life questionnaire. CONCLUSIONS: This registry followed up patients with early-stage breast cancer at 1 and 2 years after breast-conserving surgery and EBT. No recurrences have been reported, and adverse effects were acceptable.