Isolation and structural characterization of tetra-n-propyl zirconate in hydrocarbon solution and the solid state.

Tetra-n-propyl zirconate has been purified by vacuum distillation and isolated as an extremely moisture sensitive, crystalline solid. According to a single-crystal X-ray diffraction study, crystalline tetra-n-propyl zirconate is composed of tetrameric Zr(4)(OPr(n))(16) (1) molecules whose Zr(4)O(16) metal-oxygen core structure has virtual C(2)(h) symmetry, the same structure observed previously for n-alkyl orthotitanates. Carbon-13 NMR spectroscopic data indicate that this core structure is retained in hydrocarbon solution. Molecule 1 has the same M(4)O(16) metal-oxygen core structure as [CH(3)C(CH(2)O)(3)](2)M(4)(OPr(i))(10), M = Ti, where the metal centers have octahedral coordination geometry, but a metal-oxygen core structure different from that of the M = Zr case, where trigonal metaprismatic coordination geometry is observed.

Synthesis and structural comparison of a series of divalent Ln(Tp(R,R)')2 (Ln = Sm, Eu, Yb) and trivalent Sm(Tp(Me2))2X (X = F, Cl, I, BPh4) complexes.

Reaction of LnI2 (Ln = Sm, Yb) with two equivalents of NaTp(Me2) or reduction of Eu(Tp(Me2))2OTf gives good yields of the highly insoluble homoleptic Ln(II) complexes, Ln(Tp(Me2))2 (Ln = Sm (1a), Yb (2a), Eu (3a)). Use of the additionally 4-ethyl substituted Tp(Me2,4Et) ligand produces the analogous, but soluble Ln(Tp(Me2,4Et))2 (1-3b) complexes. Soluble compounds are also obtained with the Tp(Ph) and Tp(Tn) ligands (Tn = thienyl), Ln(Tp(Ph))2 (Ln = Sm, 1c; Yb, 2c) and Ln(Tp(Tn))2 (Ln = Sm, 1d; Yb, 2d). To provide benchmark parameters for structural comparison the series of Sm(Tp(Me2))2X complexes (X = F, 1e; Cl, 1f; Br, 1g; I, 1h; BPh4, 1j) were prepared either via oxidation of the Sm(Tp(Me2))2 or salt metathesis from SmX3 (X = Cl, Br, I). The solid-state structures of 1-3a, 1b, 1-2c and 1e, 1f, 1h, and 1j were determined by single-crystal X-ray diffraction. The homoleptic bis-Tp complexes are all six-coordinate with trigonal antiprismatic geometries, planes of the kappa(3)-Tp ligands are parallel to one another. In the series of Sm(Tp(Me2))2X complexes the structure changes from seven-coordinate molecular compounds, with intact Sm-X bonds, for X = F, Cl, to six-coordinate ionic structures [Sm(Tp(Me2))2]X (X = I, BPh4), suitable crystals of the bromide compound could not be obtained. The dependence of the structures on the size of X is understandable in terms of the interplay between the size of the cleft that the [Sm(Tp(Me2))2](+) fragment can make available and the donor ability of the anionic group toward the hard Sm(III) center.

Tmtacn, tacn, and triammine complexes of (eta 6-arene)OsII: syntheses, characterizations, and photosubstitution reactions (tmtacn = 1,4,7-trimethyl-1,4,7-triazacyclononane; tacn = 1,4,7-triazacyclononane).

A series of (eta 6-arene)OsII complexes containing the saturated nitrogen donor ligands tmtacn, tacn, and NH3 are prepared and characterized. The electrochemical properties and photochemical reactions of these complexes are studied, and the solid-state structures for [(eta 6-p-cymene)Os(tacn)](PF6)2 (1) and [(eta 6-p-cymene)Os(tmtacn)](PF6)2 (2) are determined. Single-crystal X-ray data: 1, orthorhombic, space group Pbca-D2h15 (No. 61), with a = 14.716(3) A, b = 17.844(3) A, c = 18.350(4) A, V = 4819(2) A3, and Z = 8; 2, monoclinic, space group C2-C2(3) (No. 5), with a = 17.322(4) A, b = 10.481(3) A, c = 15.049(4) A, beta = 98.72 degrees, V = 2701(1) A3, and Z = 4.

The Rhnull phenotype in an English individual: haematological, serological and immunological studies.

We have characterized the first case of Rhnull phenotype to be identified in England. The red cells were serologically negative for C, c, Cw, D, E, e, f, hr B, Rh17, Lw a, Lw ab and Duclos, while the patient's serum contained anti-Rh29, which was subsequently boosted by transfusion. The Rh phenotype of the patient's son (R1r) confirmed that this was a regulator type of Rhnull in the patient. Follow up studies confirmed the presence of a mild chronic anaemia with stomatocytes and spherocytes; electron microscopy revealed the presence of cells with deep central indentations. Osmotic fragility was increased to a level intermediate between normal and hereditary spherocytic controls. The presence of ongoing haemolysis was indicated by a mild reticulocytosis and splenomegaly. The potent anti-Rh29 has made the provision of compatible blood difficult and autologous units have been frozen. The case illustrates the rare phenomenon of the Rhnull phenotype which not only causes problems for the transfusionist but should also be recognized as a cause of haemolytic anaemia secondary to a membrane defect. Blood film and Rh phenotyping are useful preliminary investigations in suspected cases.

Access to graduate education for registered nurses with nonnursing baccalaureate degrees.

This article reports a study to evaluate an option for alternate access to graduate nursing education for 85 registered nurses with nonnursing baccalaureate degrees. Using the National League for Nursing Comprehensive Achievement Test (NLN-CAT) to assess knowledge together with successful completion of a special course designed by the faculty, these applicants were admitted to an accredited graduate program in the Lienhard School of Nursing (LSN), Pace University, Pleasantville, NY. The study describes 6 full years of experience using this option. The theoretical rationale; a content analysis for the congruency of content among the NLN-CAT; the terminal objectives of the LSN baccalaureate program; the course outlines and objectives of required upper division baccalaureate nursing courses; and the content of the faculty-designed course, Matrices of Nursing Practice (NUR 589) are presented. Evaluation of NUR 589 for addressing the educational gaps of these students was based on the content analysis described together with the content analysis of the 23 NLN-CAT items incorrectly answered by 50 per cent (N = 12) of successful test takers defined as those who scored at the 70th percentile and higher. Of the 85 successful candidates, 22 did not enter the program, 20 entered and did not complete the program, and 43 were graduated, 6 with distinction. Their grade point averages (GPAs) ranged from 3.37 to 4.00. Results support this method of selection of qualified candidates for graduate education.

Sensory-evoked potentials in rats chronically exposed to trichloroethylene: predominant auditory dysfunction.

Sensory-evoked potentials (EPs) were studied in male Long-Evans and Fischer-344 rats in order to characterize the electrophysiological consequences of chronic inhalation exposure to trichloroethylene (TCE). Groups of ten Long-Evans rats were exposed to air or 1600 ppm or 3200 ppm TCE for twelve weeks and evaluated periodically with a multisensory test battery. Brainstem auditory-evoked response (BAER) amplitudes were depressed by TCE, whereas somatosensory and visual potentials remained normal. The effects on BAERs, which varied with tone intensity and frequency, suggested that TCE causes a predominantly high-frequency hearing loss. Comparable effects were obtained in both strains of rats and were like those previously observed following exposure to toluene.

Breaking away: how District 16, New York State Nurses Association got started.

This paper will describe the series of events from 1938-1942 that led to the creation of a new district for nurses in Westchester County. Historical data on the context of nursing are included. Primary sources from the archives of NYSNA District 13 and 16 provided the background information. In addition, selected oral history interviews provided data for the narrative, which is primarily of a descriptive nature.

Metal oxide chemistry in solution: the early transition metal polyoxoanions.

Many of the early transition elements form large polynuclear metal-oxygen anions containing up to 200 atoms or more. Although these polyoxoanions have been investigated for more than a century, detailed studies of structure and reactivity were not possible until the development of modern x-ray crystallographic and nuclear magnetic resonance spectroscopic techniques. Systematic studies of small polyoxoanions in inert, aprotic solvents have clarified many of the principles governing their structure and reactivity, and also have made possible the preparation of entirely new types of covalent derivatives such as CH(2)Mo(4)O(15)H(3-), C(5)H(5)TiMo(5)O(18)(3-), and (OC)(3)Mn(Nb(2)W(4)O(19))(3-). Since most early transition metal polyoxoanions have structures based on close-packed oxygen arrays containing interstitial metal centers, their chemistry offers a rare opportunity to study chemical transformations in detail on well-defined metal oxide surfaces.

Metal cluster chemistry: Structure and stereochemistry in the polynuclear rhodium hydrides H(n)Rh(n)[P(OR)(3)](2n).

Crystallographic analyses of x-ray and neutron diffraction data have provided a definitive structural representation of {HRh[P(O-i-C(3)H(7))(3)](2)}(2) and {HRh[P(OCH(3))(3)](2)}(3). These polynuclear hydrides are generated from square planar H(2)Rh[P(OR)(3)](2) units by edge (hydrogen atom) sharing and by vertex (hydrogen atom) sharing to form the dimeric and trimeric structures, respectively. The square-planar units are held together through four-center and three-center two-electron Rh-H-Rh bonds in the dimer and trimer, respectively. The dimer and trimer molecules each add one molecule of hydrogen to form H[(i-C(3)H(7)O)(3)P](2)RhH(3)Rh [P(O-i-C(3)H(7))(3)](2) and H(5)Rh(3)[P(OCH(3))(3)](6), respectively. NMR spectral information has served to define the stereochemical features of these polyhydrides. The significance of this chemistry in the metal cluster-metal surface analogy is described.

Chemistry of low-valent molybdenum phosphite complexes: Models of seven-coordinate reaction intermediates.

A simple synthesis of the zerovalent complex Mo[P(OCH(3))(3)](6) has been devised from a potassium reduction of MoCl(4)(tetrahydrofuran)(2) followed by reaction with trimethyl phosphite at 70 degrees . Protonation of this octahedral complex gave only low yields of the expected seven-coordinate hydride, HMo[P(OCH(3))(3)](6) (+). The major product was an octahedral nonhydridic cation, Mo[P(OCH(3))(3)](5)P(OCH(3))(2) (+), derived from proton cleavage of the P-O phosphite ester bond. This octahedral cation was stereochemically nonrigid, apparently through facile methoxy group migration. Close packing by methoxy groups in this fluxional cation was established through an x-ray crystallographic study of Mo[P(OCH(3))(3)](5)P(OCH(3))(2) (+)-PF(6) (-). Extended reaction of trifluoroactic acid with Mo[P(OCH(3))(3)](6) yielded the seven-coordinate hydride, HMo[P(OCH(3))(3)](4)(O(2)CCF(3)), which was near pentagonal bipyramidal and was stereochemically nonrigid.

HYPERLIPIDEMIA IN AN ADULT DIABETIC POPULATION.

Of 98 adult-onset diabetic patients selected at random from an ambulatory clinic, 37.8 per cent were found to have hyperlipidemia. In follow-up examination of the hyperlipidemic patients, 23 per cent had hyper-ß-lipoproteinemia (Type II), 58 per cent had hyper-pre-ß-lipoproteinemia (Type IV), 13 per cent had increased plasma ß-and pre-ß-lipoproteins (combined type) and 6 per cent had reverted to normal values. Type IV patients, as a group, were distinguished by greater hyperglycemia and relative body weight. Chylomicronemia was not observed in this study group. Hyperlipoproteinemia was frequent in this adult-onset diabetic population and differed in several respects from similar data in untreated juvenile-onset diabetes reported by others.