A study on Zr-Ir multiple bonding active for C-H bond cleavage.

Zr-Ir hydrido complexes with ansa-(cyclopentadienyl)(amide) as the supporting ligand in the zirconium fragment, e.g., (L(1)ZrR)(Cp*Ir)(µ-H)3 [L(1) = Me2Si(η(5)-C5Me4)(N(t)Bu), R = Cl (5), Ph (7), Me (10), alkyl, and aryl] were designed, synthesized, and isolated as tractable early-late heterodinuclear complexes. Despite the presence of the three supporting hydride ligands, Zr-Ir distances in the crystal structures of 5, alkyl, and aryl complexes [2.74-2.76 Å] were slightly longer than the sum of the element radii of Zr and Ir [2.719 Å]. These hydrocarbyl complexes displayed the thermolytic C-H activation of a variety of aromatic compounds and several organometallic compounds. Also, the substrate scope and limitation in the Zr-Ir system were studied. The regiochemical outcomes during the C-H activation of pyridine derivatives and methoxyarenes suggested the in situ generation of a Lewis acidic active intermediate, i.e., (L(1)Zr)(Cp*IrH2) (III). The existence of III and relevant σ-complex intermediates {L(1)Zr(η(2)-R-H)}(Cp*IrH2) (IIR) (R = Me, Ph) in the ligand exchange was demonstrated by the direct isolation of a Et3PO-adduct of III (39b) from 7 and kinetic studies. The structure of the direct Zr-Ir bonds in IIPh, IIMe, III, and 39b were probed using computational studies. The unprecedented strong M-M' interactions in the early-late heterobimetallic (ELHB) complexes have been proposed herein.

Aluminum-stabilized low-spin iron(II) hydrido complexes of 1,4,7-trimethyl-1,4,7-triazacyclononane.

We investigated herein the reactions of (Me3tacn)FeCln (1a: n = 3, 1b: n = 2) with common aluminum hydride reagents and a bulky dihydridoaluminate {Li(ether)2}{Al(OC6H3-2,6-(t)Bu2)}(µ-H)2, which yielded the diamagnetic hydrido complexes 2-4 containing Fe(II) and Al(III). In particular, the use of divalent 1b afforded excellent isolated yields. The structures of 2-4 were determined using spectroscopic and crystallographic analyses. The crystal structures showed distorted octahedral Fe centers and fairly short Fe-Al distances [2.19-2.24 Å]. The structures of cation moiety 2 and neutral complex 4 were further probed using DFT calculations, which indicated a stable low-spin Fe(II) state and strongly electron-donating nature of the (Me3tacn)FeH3 fragment toward the Al(III) center.

Laparoscopic resection of an epidermal inclusion cyst at the vaginal cuff.

An epidermal inclusion cyst rarely occurs at the vaginal cuff, whereas it sometimes develops at the vulva and the site of episiotomy due to entrapment of the squamous epithelium. We present the case of a 58-year-old woman who developed an epidermal cyst at the vaginal cuff 6 years after laparoscopic hysterectomy. Although we could not make a precise diagnosis at imaging before the operation, the cyst was completely removed at laparoscopic surgery without any complications. To our knowledge, this is the first report of an epidermal inclusion cyst at the vaginal cuff that was successfully treated at laparoscopic surgery. Laparoscopic surgery was useful in magnifying the surgical field and in delicate manipulation of various devices to resect this pelvic floor tumor that required adhesiolysis of surrounding organs.