Comparison of myocardial ischemia during intense mental stress using flight simulation in airline pilots with coronary artery disease to that produced with conventional mental and treadmill exercise stress testing.

Mental stress increases cardiovascular morbidity and mortality. Although laboratory mental stress often causes less myocardial ischemia than exercise stress (ES), it is unclear whether mental stress is intrinsically different or differences are due to less hemodynamic stress with mental stress. We sought to evaluate the hemodynamic and ischemic response to intense realistic mental stress created by modern flight simulators and compare this response to that of exercise treadmill testing and conventional laboratory mental stress (CMS) testing in pilots with coronary disease.

Bismuth aryloxides.

The synthesis and full characterization (mp, NMR, UV/vis, FTIR, and elemental analysis) of 13 bismuth aryloxides are reported. We have prepared bismuth aryloxides with alkyl, aryl, and allylic substituents on the aryl rings. Eleven of these bismuth aryloxides have been characterized with single crystal X-ray diffraction methods.

Facile synthesis of bismuth(III) and antimony(III) complexes supported by silylated calix[5]arenes.

A series of bismuth(III) and antimony(III) complexes supported by silicon-containing calix[5]arene ligands were synthesized and fully characterized by NMR, X-ray, IR, mp, UV/vis, and elemental analysis. Reaction of the para-tert-butylcalix[5]arene [(t)BuC5(H)(5)] disodium salt, Na(2) x (t)BuC5(H)(3), with 1 equiv of R(2)SiCl(2) (R = Me, (i)Pr, Ph, CH=CH(2)) or treatment of the (t)BuC5(H)(5) lower rim monobenzyl ether [(t)BuC5(Bn)(H)(4)] in a 1:1 ratio with Me(2)Si(NMe(2))(2) yields the (t)BuC5(SiRR')(H)(3) (1-5) and (t)BuC5(Bn)(SiMe(2))(H)(2) (6) ligands, respectively. The (1)H NMR spectra of the (t)BuC5(SiRR')(H)(3) (1-5) ligands show three pairs of doublets and three singlets for the (t)Bu peaks, consistent with a C(s) symmetry.

Synthesis of bismuth and antimony complexes of the "larger" calix[n]arenes (n=6-8); from mononuclear to tetranuclear complexes.

A series of calix[n]arene (n=6-8) bismuth and antimony complexes were synthesized and fully characterized by NMR, X-ray, IR, UV-Vis and elemental analysis. The monobismuth calix[6]arene complex [Bi{tBuC6(H)3}]2 1 was prepared by the reaction of para-tert-butylcalix[6]arene (tBuC6(H)6) with one equivalent of Bi[N(SiMe3)2]3. Complex 1 featured a Bi2(micro-O)2 central core similar to other bismuth calixarene complexes prepared by our group.

Synthesis, X-ray structures and reactivity of calix[5]arene bismuth(iii) and antimony(III) complexes.

A series of calix[5]arene bismuth(III) and antimony(III) mono- and bimetallic complexes were synthesized and fully characterized by NMR, X-ray, IR, mp, UV-Vis and elemental analysis. Reaction of p-tert-butylcalix[5]arene (tBuC5(H)5) trianionic salts M'3.tBuC5(H)2 (M'=Li, Na, K) with MCl3 (M=Bi, Sb) yielded monometallic complexes [Bi{tBuC5(H)2}] 1 and [Sb{tBuC5(H)2}] 2, respectively.

Heterobimetallic bismuth(III)/molybdenum(VI) and antimony(III)/molybdenum(VI) calix[5]arene complexes. Progress toward modeling the SOHIO catalyst.

The treatment of the monometallic bismuth or antimony complexes [M{(t)BuC5(H)(2)}] (M = Bi, Sb) with 1.5 equiv of MoO(2)(O(t)Bu)(2) in 1,2-dimethoxyethane (DME) produced soluble Bi(III)/Mo(VI) and Sb(III)/Mo(VI) heterometallic calix[5]arene complexes [Bi(2)Mo(4)O(11){(t)BuC5(H)}(2)] 1 and [Sb(2)Mo(4)O(11){(t)BuC5(H)}(2)] 2 in 55 and 45% yields, respectively. In solution the (1)H NMR patterns for 1 and 2 are characteristic of a C(s) symmetry with three pairs of doublets for the methylene protons and three singlets in a 1:2:2 ratio for the tert-butyl groups.

Synthesis and characterization of bismuth(III) and antimony(III) calixarene complexes.

A series of calixarene bismuth and antimony complexes have been fully characterized by NMR, X-ray, IR, UV/vis, and elemental analysis. The reactions of SbCl(3) with the monosodium salt of p-tert-butylcalix[4]arene (Bu(t)C4), Bu(t)C4.Na, and the tetralithium salt of para-tert-butylcalix[4]arene, Bu(t)C4.

Molybdocalixarene structure control via rim deprotonation. synthesis, characterization, and crystal structures of calix[4]arene Mo(VI) monooxo complexes and calix[4]arene alkali metal/Mo(VI) dioxo complexes.

We report a series of calix[4]arene Mo(VI) dioxo complexes M2RC4MoO2 (M = alkali metal, R = H or Bu(t)) that were fully characterized by NMR, X-ray, IR, UV/vis, and elemental analysis. Molybdocalix[4]arene structures can be controlled via lower rim deprotonation, groups at para positions of calix[4]arene, and alkali metal counterions. Mono deprotonation at the lower rim leads to calix[4]arene Mo(VI) monooxo complexes RC4MoO (R = H, Bu(t), or allyl), and full deprotonation gives rise to calix[4]arene Mo(VI) dioxo complexes.

Facile formation of molybdenum(VI) monooxo aryloxides MoO(OAr)4-nCln from molybdenum dioxo dichloride.

Molybdenum monooxo compoundsMoO(OAr)4-nCln (n=0-2, Ar=2,6-Me2C6H3 or 2,6-i-Pr2C6H3) have been synthesized starting from the dioxo precursor MoO2Cl2. The complexes are characterized spectroscopically and by X-ray diffraction. The formation mechanism likely involves phenol precoordination followed by addition across the Mo=O bond.

Synthesis and X-ray crystal structures of the first antimony and bismuth calixarene complexes.

The reaction of the monosodium salt of p-tert-butylcalix[4]arene (But)C4) with 2 equivalents of SbCl3 provides ButC4(SbCl)2 and the first bismuth calixarene complex was prepared by treatment of p-tert-butylcalix[8]arene (ButC8) with Bi[N(SiMe3)2]3 in toluene.

Steric control of coordination number: A series of Mo(VI) dioxo diaryloxide complexes bearing 4-, 5-, and 6-coordinate environments.

The design, synthesis, and structure determination of a series of Mo(VI) dioxo diaryloxide complexes have been reported. By varying the steric bulk of the aryloxide ligand, control of the coordination number around the Mo(VI) center was achieved. All the complexes are characterized by analytical and spectroscopic techniques.

Synthesis, structures, and conformational characteristics of calixarene monoanions and dianions.

The synthesis, complete characterization, and solid state structural and solution conformation determination of calix[n]arenes (n = 4, 6, 8) is reported. A complete series of X-ray structures of the alkali metal salts of calix[4]arene (HC4) illustrate the great influence of the alkali metal ion on the solid state structure of calixanions (e.g.

Evidence for an unstable Bi(II) radical from Bi-O bond homolysis. Implications in the rate-determining step of the SOHIO process.

The reaction of BiCl(3) with the lithium salt of o-di-tert-butylphenol under nitrogen forms organic oxidation products rather than the expected Bi(OAr)(3) complex, and bismuth disproportionation products. Likewise, the decomposition of Bi(III) aryloxides Bi(O-2,6-(i)Pr(2)C(6)H(3))(3) and ClBi(O-2,4,6-(t)Bu(3)C(6)H(2))(3) leads to corresponding organic oxidation products. These reactions can be explained by Bi-O bond homolysis to form unstable Bi(II) radicals, analogous to a fundamental step suggested to intervene in the SOHIO process.

Reactivity of Zirconocene Azametallacyclobutenes: Insertion of Aldehydes, Carbon Monoxide, and Formation of alpha,beta-Unsaturated Imines. Formation and Trapping of [Cp(2)Zr=O] in a [4 + 2] Retrocycloaddition(1).

Azametallacyclobutene Cp(2)ZrN-t-BuCEt=CEt (1) underwent an insertion reaction with CO to form the acyl complex 2 (Cp(2)Zr(N-t-BuCEtCEtCO), 67% yield). The addition of acetone to azametallacyclobutene 3 (Cp(2)Zr(NArCMeCPh), Ar = 2,6-dimethylphenyl) yielded the N-bonded enamine and O-bonded enolate complex of zirconocene 4 (Cp(2)Zr(NArCMeCPhH)(OCMeCH(2)), 76% yield). The addition of aldehydes RCOH to metallacycle 3 resulted in the insertion of the aldehyde into the Zr-C bond to form complexes Cp(2)Zr(NArCMeCPhCRHO) (8a) and Cp(2)Zr(NArCMeCPhC(i-Pr)HO (9) in 85% (R = Ph) and 73% yields, respectively.