Isolation and X-ray Structures of Labile Benzoic- and Acetic-Acidium Carbocations

New carbocationic salts (via O-protonation of substituted benzoic acids) are prepared for the first time by controlled hydration of the corresponding benzoylium salts and isolated in pure crystalline form. Precise X-ray structural analyses reveal the rather unexpected (electronic) structure of the carboxylic-acidium functionality

Isolation, X-ray Structures, and Electronic Spectra of Reactive Intermediates in Friedel−Crafts Acylations

Reactive intermediates in the Friedel−Crafts acylation of aromatic donors are scrutinized upon their successful isolation and X-ray crystallography at very low temperatures. Detailed analyses of the X-ray parameters for the [1:1] complexes of different aliphatic and aromatic-acid chlorides with the Lewis acids antimony pentafluoride and pentachloride, gallium trichloride, titanium and zirconium tetrachlorides provide unexpected insight into the activation mechanism for the formation of the critical acylium carbocations. Likewise, the X-ray-structure examinations of aliphatic and aromatic acylium electrophiles also isolated as crystalline salts point to the origins of their electrophilic reactivity. Although the Wheland intermediates (as acylium adducts to arene donors) could not be isolated in crystalline form owing to their exceedingly short lifetimes, transient (UV−vis) spectra of benzenium adducts of acylium carbocations with hexamethylbenzene can be measured and directly related to Wheland intermediates with other cationic electrophiles that have been structurally established via X-ray studies

Notes on Stein-Sahi representations and some problems of non L2L^2 harmonic analysis

We discuss one natural class of kernels on pseudo-Riemannian symmetric spaces.Comment: 40p

Infinite-dimensional pp-adic groups, semigroups of double cosets, and inner functions on Bruhat--Tits builldings

We construct $p$-adic analogs of operator colligations and their characteristic functions. Consider a $p$-adic group $G=GL(\alpha+k\infty, Q_p)$, its subgroup $L=O(k\infty,Z_p)$, and the subgroup $K=O(\infty,Z_p)$ embedded to $L$ diagonally. We show that double cosets $\Gamma= K\setminus G/K$ admit a structure of a semigroup, $\Gamma$ acts naturally in $K$-fixed vectors of unitary representations of $G$. For each double coset we assign a 'characteristic function', which sends a certain Bruhat--Tits building to another building (buildings are finite-dimensional); image of the distinguished boundary is contained in the distinguished boundary. The latter building admits a structure of (Nazarov) semigroup, the product in $\Gamma$ corresponds to a point-wise product of characteristic functions.Comment: new version of the paper, 47pp, 3 figure

Step-Wise Computational Synthesis of Fullerene C60 derivatives. 1.Fluorinated Fullerenes C60F2k

The reactions of fullerene C60 with atomic fluorine have been studied by unrestricted broken spin-symmetry Hartree-Fock (UBS HF) approach implemented in semiempirical codes based on AM1 technique. The calculations were focused on a sequential addition of fluorine atom to the fullerene cage following indication of the cage atom highest chemical susceptibility that is calculated at each step. The effectively-non-paired-electron concept of the fullerene atoms chemical susceptibility lays the foundation of the suggested computational synthesis. The obtained results are analyzed from energetic, symmetry, and the composition abundance viewpoints. A good fitting of the data to experimental findings proves a creative role of the suggested synthesis methodology.Comment: 33 pages, 11 figures, 2 tables, 2 chart

Первичный спонтанный пневмоторакс и дисплазия соединительной ткани: клинико-морфологические параллели

The objective of this study was to define pathologic mechanisms of primary spontaneous pneumothorax in patients with connective tissue dysplasia (CTD). Methods. We followed-up 42 young patients with CTD and bullous emphysema in the lung CT without history of primary spontaneous pneumothorax. Results of clinical, functional, radiological and molecular testing were compared with morphological examination of resected lung tissue specimens from 165 patients underwent lung surgery for primary spontaneous pneumothorax. Results. Two mechanisms underlying emphysema in CTD patients were defined. Conclusion: The results supported a hypothesis of causative relationship between congenital CTD and bullous emphysema in young patients.Цель исследования: уточнение механизмов возникновения первичного спонтанного пневмоторакса у пациентов с дисплазией соединительной ткани (ДСТ). Материалы и методы. Проведено обследование 42 пациентов молодого возраста с буллезным вариантом бронхолегочного синдрома при ДСТ без эпизодов спонтанного пневмоторакса в анамнезе. Данные клинико-функционального, рентгенологического и молекулярно-генетического обследования сопоставлены с морфологическими находками, полученными при исследовании резектатов легких 165 пациентов, которым было проведено оперативное вмешательство по поводу первичного спонтанного пневмоторакса.Результаты. При клинико-морфологическом сопоставлении выявлены определенные закономерности, позволившие выделить 2 патологических процесса, лежащих в основе формирования эмфиземы у пациентов с ДСТ.Выводы. Полученные данные подтверждают гипотезу о наличии причинно-следственной связи между наследственными нарушениями соединительной ткани и формированием буллезной эмфиземы у лиц молодого возраста

Introduction to representations of the canonical commutation and anticommutation relations

Lecture notes of a minicourse given at the Summer School on Large Coulomb Systems - QED in Nordfjordeid, 2003, devoted to representations of the CCR and CAR. Quasifree states, the Araki-Woods and Araki-Wyss representations, and the lattice of von Neumenn algebras in a bosonic/fermionic Fock space are discussed in detail

THE ERRORS, COMPLICATIONS AND MEASURES FOR ITS PREVENTION IN THE TREATMENT OF SCHOOL AGE CHILDREN WITH CONGENITAL RECURRENT CLUBFOOT BY ILIZAROV METHOD

Objective. To analyze the errors and complications of treatment of school age children with congenital recurrent clubfoot, treated in RISC «RTO» by transosseous osteosyntesis. Material and methods. Within the period of 1999-2010 119 patients (148 feet) between the ages of 7 to 18 years with congenital recurrent clubfoot were treated by the Ilizarovs method. Patients of this group, along with holding the wires on the shin and foot, corresponding to the Ilizarov fixator assembly, received surgical procedures on soft tissue, osteotomy and stabilizing operations. Results. In the course of treatment complications were observed in 22 patients, accounted for 18.5% of the total number of patients. All complications were typical for transosseous osteosynthesis, eliminated during a course of treatment and did not affect his final result. Conclusion. Adherence to the methodical principles of transosseous osteosynthesis by Ilizarov in the surgical treatment of patients of school age with recurrent congenital clubfoot and rational management of patients in the postoperative period is the prevention of complications and contributes to achieving good results