N_2 Functionalization at Iron Metallaboratranes

The reactivity of the anionic dinitrogen complex [(TPB)Fe(N_2)]^− (TPB = tris[2-(diisopropylphosphino)phenyl]borane) toward silicon electrophiles has been examined. [(TPB)Fe(N_2)]^− reacts with trimethylsilyl chloride to yield the silyldiazenido complex (TPB)Fe(NNSiMe_3), which is reduced by Na/Hg in THF to yield the corresponding sodium-bound anion [(TPB)Fe(NNSiMe_3)]Na(THF). The use of 1,2-bis(chlorodimethylsilyl)ethane in the presence of excess Na/Hg results in the disilylation of the bound N_2 molecule to yield the disilylhydrazido(2−) complex (TPB)Fe≡NR (R = 2,2,5,5-tetramethyl-1-aza-2,5-disilacyclopentyl). One of the phosphine arms of TPB in (TPB)Fe≡NR can be substituted by CO or ^tBuNC to yield crystalline adducts (TPB)(L)Fe≡NR (L = CO, ^tBuNC). The N–N bond in (TPB)(^tBuNC)Fe≡NR is cleaved upon standing at room temperature to yield a phosphoraniminato/disilylamido iron(II) complex. The flexibility of the Fe–B linkage is thought to play a key role in these transformations of Fe-bound dinitrogen

Functional Generative Design: An Evolutionary Approach to 3D-Printing

Consumer-grade printers are widely available, but their ability to print complex objects is limited. Therefore, new designs need to be discovered that serve the same function, but are printable. A representative such problem is to produce a working, reliable mechanical spring. The proposed methodology for discovering solutions to this problem consists of three components: First, an effective search space is learned through a variational autoencoder (VAE); second, a surrogate model for functional designs is built; and third, a genetic algorithm is used to simultaneously update the hyperparameters of the surrogate and to optimize the designs using the updated surrogate. Using a car-launcher mechanism as a test domain, spring designs were 3D-printed and evaluated to update the surrogate model. Two experiments were then performed: First, the initial set of designs for the surrogate-based optimizer was selected randomly from the training set that was used for training the VAE model, which resulted in an exploitative search behavior. On the other hand, in the second experiment, the initial set was composed of more uniformly selected designs from the same training set and a more explorative search behavior was observed. Both of the experiments showed that the methodology generates interesting, successful, and reliable spring geometries robust to the noise inherent in the 3D printing process. The methodology can be generalized to other functional design problems, thus making consumer-grade 3D printing more versatile.Comment: 8 pages, 12 figures, GECCO'1

The Miseducation of Public Citizens

The American Bar Association Model Rules of Professional Conduct calls upon lawyers, as public citizens, to embrace a special responsibility for the quality of justice in the legal profession and in society. Yet, some law professors have historically adopted a formalistic and doctrinally neutral approach to law teaching that elides critical perspectives of law, avoids the intersection of law and politics, and tends to overlook the way law can construct the very social injustices that it seeks to contain. The objective, apolitical, and so-called “colorblind” jurisprudential stance in many law classrooms inflicts intellectual violence upon law students who discover a legal doctrine in conflict with their own lived experiences, yet who feel silenced and unprepared to reckon with the moral legitimacy of unjust laws. Perhaps as a result, in recent years, law schools have begun to rethink legal education altogether, devising anti-racist curricula, professional identity trainings, and novel experiential learning programs to produce a new generation of critically conscious lawyers for the crises of our modern age. Building upon such efforts, alongside recent scholarship in legal education and philosophical legal ethics, this Essay proposes foundational pedagogical principles to teach public citizenship lawyering. This Essay defines public citizenship lawyering as a democratic conception of professional responsibility whereby lawyers engage in routine critique of their lawyering practice through the lens of justice as a moral virtue. This pedagogy finds normative grounding in the ABA Model Rules based upon the contention that a skewed vision of professional lawyering identity has hindered a justice-oriented interpretation of the lawyer’s public citizen charge. Specifically, this Essay articulates four pedagogical principles: (1) deconstructive framing, which guides the law professor in teaching the lawyer’s ethical duty of candor; (2) ethical reposturing, which guides the law professor in teaching the lawyer’s ethical duty of competence and professional judgment; (3) reconstructive ordering, which guides the law professor in teaching the lawyer’s ethical duty to improve the law; and (4) liberatory lawyering, which guides the law professor in teaching the lawyer’s ethical duty to assist the client and others in gaining competence. Collectively, these principles assert a counter-cultural vision of practice readiness that empowers law students to affirmatively challenge social and economic injustice in the legal profession and the rule of law. More than exalting a democratic conception of professional lawyering identity, these principles affirm the legal academy as law’s laboratory for progressive social change

Black Urban Ecologies and Structural Extermination

Residents of low-income, metropolitan communities across the United States frequently live in “food apartheid” neighborhoods—areas with limited access to nutrient-rich and fresh food. Local government law scholars, poverty law scholars, and political theorists have long argued that structural racism embedded in America’s political economy influences the uneven development of such Black urban ecologies. Accordingly, food justice scholars have called for local governments to develop urban agricultural markets that combat racism in global corporatized food systems by localizing food development. These demands have only amplified during the COVID-19 pandemic, which has ravaged Black communities where residents suffer from preexisting health conditions and weakened immune systems associated with food insecurity. However, while local governments are increasing development of urban agriculture in Black urban spaces, in some instances, this has only driven Black and minoritized residents to compete against one another for access to healthy food and scarce farmland. Thus, the development of urban agriculture may function to recreate the very problems of racial capitalism and neoliberalism embedded in America’s political economy that animate food insecurity in the first place. This Article argues that urban agriculture imbued with racial capitalist norms and neoliberal politics—e.g., “neutral” and “colorblind” policies that ignore historic state-sponsored racial discrimination, limit governmental market interventions, and promote individualistic competition and private ownership—will fail to mitigate the structural oppression that drives food insecurity in Black urban landscapes marred by environmental degradation, or Black urban ecologies. Instead, such forces distort urban agriculture into a weapon of exploitation, expropriation, and erasure, each foundational elements of a social theory of ecological systems change this Author calls structural extermination. This Article illustrates the theory of structural extermination, which has broad explanatory power, by examining Washington, D.C.’s history of urban farming legislation, beginning with the passage of the Food Production and Urban Gardens Program Act of 1986 and continuing, most recently, with the Urban Farming Land Lease Amendment Act of 2019. By documenting a visible shift in political discourse about Washington, D.C.’s urban farming program, from a community-oriented initiative for gardening and food donation to a market-centered program for land leasing and tax abatement, this analysis reveals how decontextualized and dehistoricized urban agriculture risks legitimating and rationalizing competitive market structures that enact violence upon the poor, and push low-income residents out of the city altogether. Finally, this Article calls for the democratization of ecological placemaking in Black urban geographies, a decolonial praxis that would embrace a justice-based vision of community economic development premised upon the principles of social solidarity, economic democracy, and solidarity economy

Blackness as Fighting Words

The resurgence of worldwide protests by activists of the Movement for Black Lives (BLM) has ushered a global reckoning with the meaning of this generation’s rallying cry – “Black Lives Matter.” As citizens emblazon their streets with this expression in massive artistic murals, the Trump administration has responded with the militarized policing of non-violent public demonstrations, revealing not merely a disregard for public safety, but far worse, a concerted dismantling of protestors’ First Amendment rights. Nevertheless, BLM protests have persisted. Accordingly, this Essay considers the implications of this generation’s acclamation of Black humanity amidst the social tensions exposed during the era of COVID-19. What does the Trump administration’s militarized response to BLM protests mean in a world mutilated by the scars of racial oppression, a wound laid bare by America’s racially biased, aggressive, and supervisory culture of policing? In response, much in the way Cheryl Harris revealed Whiteness as Property, this Essay suggests and defends Black identity itself, or Blackness – whether articulated by the pure speech of racial justice activists who affirm Black humanity, or embodied by the symbolic speech of Black bodies assembled in collective dissent in the public square – as “fighting words” in the consciousness of America, a type of public speech unprotected by the Constitution. The very utterance of the phrase “Black Lives Matter” tends to incite imminent violence and unbridled rage from police in city streets across America. Discussions of “Black Lives Matter” by pundits conjure images of subversion, disorder, and looting, the racialized narratives of social unrest commonly portrayed by the media. Yet, the words “Black Lives Matter” and the peaceful assembly of Black protestors also encapsulate the fire of righteous indignation burning in the hearts of minoritized citizens. This dynamic reflects unresolved tensions in the First Amendment’s treatment of race relations in America. Even more, it exposes the role of policing in smothering the Constitutional rights of Black and Brown citizens. This Essay provides three contributions to the ongoing discourse on policing in the United States. First, it reveals how unresolved racial tensions in the First Amendment – focusing specifically on ambiguities in the fighting words doctrine – perpetuate the racially biased, aggressive, and supervisory culture of American policing. Second, it analyzes how such unresolved racial tensions cast a dark shadow over the liberty of Black and Brown citizens who experience racism at the hands of police officers, yet avoid acts of protest for fear of bodily harm or arrest. Third, it illuminates the embeddedness of racism in American policing culture, more generally; a culture that not only constructs and reconstitutes the racial social order, but also degrades the dignity of Black and Brown citizens. Collectively, these insights lend support toward demands for police abolition from BLM activists. As this Essay concludes, until we as a nation wrestle with the unresolved racial subtext of modern policing – a racist culture woven into law that not only silences the legitimate protests of minoritized citizens in violation of their First Amendment rights, but also rationalizes callous violence at the hands of law enforcement – Black America will remain a peril to the veil of white supremacy that looms over the American constitutional order