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This chapter is structured around the provocative claim that African Americans are natural diplomats because of the particular circumstances of the black experience in the United States. In order to survive, African Americans have been conditioned to mask their frank judgments about the American “democratic” system. Within this framework, the chapter conceptualizes a so-called “New Negro foreign folicy.” As embodied in the work of Locke and Bunche, this perspective is characterized by a critical approach to foreign policy, albeit one that is not too radical or too applicable to the American domestic racial context so as to avoid offending white liberal sensibilities (and therefore jeopardizing patronage opportunities). Representative of sequential stages of development within this foreign policy tradition, Locke and Bunche encountered different levels of political access and policy influence.

This study examined discursive choices made by the instructor of a Black Studies course in constructing what counted as blogging and the history of jazz; how students showed evidence of meeting the course requirements, and how particular students engaged with issues of race and diversity in their blogs. The instructor required blogging to enable an interactional form of learning that supported development of a writing voice, criticality, and thinking in interdisciplinary ways. Students entered the course having different prior experiences and understandings of jazz and the class format allowed students to move from whatever path they were on to embrace the positive nature of diversity in the creation of culture.

No abstract for this article.

No abstract for this article.

A strategy for polymerization catalyst design has been developed based on the steric and electronic analogy of bulky phosphinimides to cyclopentadienyl ligands. To this end, the family of complexes of the form (Cp†)TiCl2(NPR3) has been prepared and characterized. Alkyl and aryl derivatives of these species have also been synthesized, and a number have been evaluated for use as catalyst precursors in olefin polymerization. The polymerization of ethylene has been examined employing several types of cocatalyst activators. Trends and patterns in the structure−activity relationship are discussed, and the implications for catalyst design are evaluated.

Multiple C−H bond activation occurs upon reaction of phosphinimide complexes of the form Cp‘(R3PN)TiMe2 (Cp‘ = Cp, indenyl; R = i-Pr, Cy, Ph) with excess AlMe3, affording the carbide complexes Cp‘Ti(μ2-Me)(μ2-NPR3)(μ4-C)(AlMe2)3 or in some cases [CpTi(μ2-Me)(μ2-NPR3)(μ5-C)(AlMe2)3·(AlMe3)]. These species contain four- and five-coordinate carbide centers. VT-NMR studies established that such species exist in equilibrium. The four-coordinate carbide complexes retain Lewis acidity at a planar three-coordinate Al center, as evidenced by the reaction with diethyl ether, THF, or PMe3. This affords species of the form [CpTi(μ2-Me)(μ2-NPR3)(μ4-C)(AlMe2)2(AlMe2(L))] (L = Et2O, THF, PMe3). The Lewis acidity is also evidenced in the reaction of the carbide complexes with CpTi(NPR3)Me2. In this case, labeling studies affirm methyl group exchange processes. The analogous reactions of Cp(R3PN)Ti(CH2SiMe3)2 or Cp*(R3PN)TiMe2 with AlMe3 afforded CpTi(μ2-Me)(μ2-NPR3)(μ3-CSiMe3)(AlMe2)2 and Cp*Ti(μ2-Me)(μ2-NPR3)(μ3-CH)(AlM...

The phosphinimide complexes (t-Bu3PN)TiCl3 (1) and (t-Bu3PN)2TiCl2 (4) are readily prepared in high yields from the stoichiometric reaction of t-Bu3PNSiMe3 and TiCl4, while (t-Bu3PN)3TiCl (11) is readily obtained from the reaction of t-Bu3PNLi and TiCl4. The analogous 1:1 or 2:1 reactions of ZrCl4 and t-Bu3PNLi afford mixtures of products, although in the 3:1 stoichiometric ratio (t-Bu3PN)3ZrCl (12) is isolable. These complexes are readily alkylated with a variety of reagents to give (t-Bu3PN)TiMe3 (2), (t-Bu3PN)Ti(CH2Ph)3 (3), (t-Bu3PN)2TiMe2 (5), (t-Bu3PN)2Ti(η3-C3H5)2 (6), (t-Bu3PN)2Ti(CH2Ph)2 (7), (t-Bu3PN)2TiPh2 (8), (t-Bu3PN)2Ti(η5-Cp)Cl (9), (t-Bu3PN)2Ti(η5-Cp)Me (10), (t-Bu3PN)3TiMe (13), (t-Bu3PN)3TiPh (14), (t-Bu3PN)3ZrMe (15), (t-Bu3PN)3Zr(CH2Ph) (16), and (t-Bu3PN)3Zr(η5-Cp) (17). Subsequent reactions of some of these alkyl derivatives with [PhNMe2H][B(C6F5)4], [Ph3C][B(C6F5)4], or B(C6F5)3 are investigated. A number of zwitterionic and cationic species complexes have been characterized. These...

The compounds CpTiCl 2 (OC 6 H 3 - i -Pr 2 ) ( 1 ), CpTiCl(OC 6 H 3 - i- Pr 2 ) 2 ( 2 ), CpTi(R)(OC 6 H 3 - i -Pr 2 ) 2 (R= t -Bu 3 , s -Bu 4 , n -Bu 5 , Me 6 ) have been prepared and characterized. Compounds 1 or 2 in the presence of 500 equivalents of methylaluminoxane (MAO) act as catalyst precursors for ethylene polymerization. While the catalysts derived from the monocyclopentadienyl complexes are much less active that the metallocenes, there is a clear enhancement in the activity of about 40% as a result of the inclusion of a second aryloxide ligand. Reactions of 1 with AlMe 3 revealed stepwise formation of CpTi(Me)Cl(OC 6 H 3 - i -Pr 2 ) 7 and CpTi(Me) 2 (OC 6 H 3 - i -Pr 2 ) 8 , while subsequent addition of AlMe 3 afforded complete conversion to 8 , with formation of the aluminum species [AlMe 2 (OC 6 H 3 - i -Pr 2 )] n 9 . In contrast, the catecholate complex CpTi(O 2 C 6 H 4 )Cl 10 reacts with AlMe 3 yielding the paramagnetic species [CpTi(O 2 (C 6 H 4 ))·AlClMe 2 ] 2 11 . Incorporation of aryloxide ligands in modified metallocenes was readily accomplished with the preparation of Cp 2 ZrCl(OC 6 H 3 - i -Pr 2 ) 12 , Cp 2 ZrCl(OC 6 H 5 ) 13 , Cp 2 ZrMe(OC 6 H 5 ) 14 and Cp 2 TiCl(OC 6 H 3 - i -Pr 2 ) 15 . In combination with MAO, 12 , 14 and 15 effect the polymerization of ethylene with an 11% increase in activity over the parent metallocenedichlorides. The implications of the increased activity are considered. Crystallographic data are reported for 2 , 3 , 6 , 9 , 11 , 12 and 13 .

Complexes of the form (Cp†)TiCl2(NPR3) and the analogous dimethyl derivatives (Cp†)TiMe2(NPR3) have been prepared. These species in the presence of MAO, B(C6F5)3, or [Ph3C][B(C6F5)4] are active catalysts for ethylene polymerization.

The purpose of this study was to develop an improved correlation for natural convection heat transfer from inclined cylinders having different emissivities. The angle of cylinder inclination varied from horizontal to vertical in 15° increments. The heat transfer coefficient was obtained experimentally with the cylinder in a state of constant heat flux. Three surface finishes were used in the experiment, which consisted of polished copper, black paint, and aluminum paint. The heat transfer coefficients in all cases varied from 1.21 to 1.65 BTU/(hr·ft2·R) [6.87 to 9.37 W/(m2·K)]. Rayeigh numbers for all experiments varied from 1.31 × 103 to 2.23 × 103. The heat transfer coefficient decreased for each cylinder with an increasing angle of inclination (from horizontal to vertical). The goal of this study was to produce Nusselt-Rayleigh number correlations for each cylinder, and then ultimately produce a single equation that can be applied for all emissivities. The Rayleigh number included a geometry term to account for the inclination of the cylinder. The form of the equation that best represented the data was a power law equation.

The diphosphines m-C6H4(CH2Pt-Bu2)21 and m-C6H4(CH2PCy2)22 were prepared and oxidized with Me3SiN3 to m-C6H4(CH2(t-Bu2)PNSiMe3)23 and m-C6H4(CH2(Cy2)PNSiMe3)24, and subsequently converted to m-C6H4(CH2(t-Bu)2PNH)25 and m-C6H4(CH2(Cy)2PNH)26. Reaction of 5 and 6 with Ti(NMe2)4 afforded the yellow compounds m-C6H4(CH2(t-Bu)2PN)2Ti(NMe2)27 and m-C6H4(CH2(Cy)2PN)2Ti(NMe2)28, and the low abundance by-product m-C6H4(CH2(t-Bu)2PN)2TiBr(NMe2) 9. In a similar manner, the species m-C6H4(CH2(t-Bu)2PN)2Zr(NEt2)210 was prepared from Zr(NEt2)4. Compounds 8, 9 and 10 were converted to C6H4(CH2(t-Bu)2PN)2TiBr211, m-C6H4(CH2(Cy)2PN)2TiCl213 and C6H4(CH2(t-Bu)2PN)2ZrCl214via reaction with Me3SiX (X = Br, Cl). Alternatively, m-C6H4(CH2(t-Bu)2PN)2TiCl212 and 13 were prepared in low yield from reaction of 3 or 4 with TiCl4. Alkylation of 11 with MeMgBr and PhCH2MgBr proceeded to give m-C6H4(CH2(t-Bu)2PN)2TiMe215 and m-C6H4(CH2(t-Bu)2PN)2Ti(CH2Ph)216, respectively. The species (m-C6H4(CH2(t-Bu)2PN)2)2Zr 17 was prepared from Zr(CH2Ph)4. These synthetic routes are described and the implications for applications in olefin polymerization catalysis are considered. X-Ray structural data for compounds 1, 3, 4, 5, 8, 9 and 16 are reported.