The ligational behavior of a phenolic quinolyl hydrazone towards copper(II)- ions

<p>Abstract</p> <p>Background</p> <p>The heterocyclic hydrazones constitute an important class of biologically active drug molecules. The hydrazones have also been used as herbicides, insecticides, nematocides, redenticides, and plant growth regulators as well as plasticizers and stabilizers for polymers. The importance of the phenolic quinolyl hydrazones arises from incorporating the quinoline ring with the phenolic compound; 2,4-dihydroxy benzaldehyde. Quinoline ring has therapeutic and biological activities whereas, phenols have antiseptic and disinfectants activities and are used in the preparation of dyes, bakelite and drugs. The present study is planned to check the effect of the counter anions on the type and geometry of the isolated copper(II)- complexes as well as the ligational behavior of the phenolic hydrazone; 4-[(2-(4,8-dimethylquinolin-2-yl)hydrazono)methyl] benzene-1,3-diol; (H₂L).</p> <p>Results</p> <p>A phenolic quinolyl hydrazone (H₂L) was allowed to react with various copper(II)- salts (Cl‾, Br‾, NO₃‾, ClO₄‾, AcO‾, SO₄^2-). The reactions afforded dimeric complexes (ClO₄‾, AcO‾ ), a binuclear complex (NO₃‾ ) and mononuclear complexes (the others; Cl‾, Br‾, SO₄^2-). The isolated copper(II)- complexes have octahedral, square pyramid and square planar geometries. Also, they reflect the strong coordinating ability of NO₃‾, Cl‾, Br‾, AcO‾ and SO₄^2-anions. Depending on the type of the anion, the ligand showed three different modes of bonding <it>viz</it>. (NN)⁰for the mononuclear complexes (<b>3, 4, 6</b>), (NO)^-with O- bridging for the dimeric complexes (<b>1, 5</b>) and a mixed mode [(NN)⁰+ (NO)^-with O- bridging] for the binuclear nitrato- complex (<b>2</b>).</p> <p>Conclusion</p> <p>The ligational behavior of the phenolic hydrazone (H₂L) is highly affected by the type of the anion. The isolated copper(II)- complexes reflect the strong coordinating power of the SO₄^2-, AcO‾, Br‾, Cl‾ and NO₃‾ anions. Also, they reflect the structural diversity (octahedral, square pyramid and square planar) depending on the type of the counter anion.</p

The ligational behavior of an isatinic quinolyl hydrazone towards copper(II)- ions

<p>Abstract</p> <p>Background</p> <p>The importance of the isatinic quinolyl hydrazones arises from incorporating the quinoline ring with the indole ring. Quinoline ring has therapeutic and biological activities whereas, the indole ring occurs in Jasmine flowers and Orange blossoms. As a ligand, the isatin moiety is potentially ambidentate and can coordinate the metal ions either through its lactam or lactim forms. In a previous study, the ligational behavior of a phenolic quinolyl hydrazone towards copper(II)- ions has been studied. As continuation of our interest, the present study is planned to check the ligational behavior of an isatinic quinolyl hydrazone.</p> <p>Results</p> <p>New homo- and heteroleptic copper(II)- complexes were obtained from the reaction of an isatinic quinolyl hydrazone (HL) with several copper(II)- salts <it>viz. </it>Clˉ, Brˉ, NO₃ˉ, ClO₄^-, SO₄^2-and AcO^-. The obtained complexes have O_h, T_dand D_4h- symmetry and fulfill the strong coordinating ability of Clˉ, Brˉ, NO₃ˉ and SO₄^2-anions. Depending on the type of the anion, the ligand coordinates the copper(II)- ions either through its lactam (NO₃ˉ and ClO₄^-) or lactim (the others) forms.</p> <p>Conclusion</p> <p>The effect of anion for the same metal ion is obvious from either the geometry of the isolated complexes (O_h, T_dand D_4h) or the various modes of bonding. Also, the obtained complexes fulfill the strong coordinating ability of Clˉ, Brˉ, NO₃ˉ and SO₄^2-anions in consistency with the donor ability of the anions. In case of copper(II)- acetate, a unique homoleptic complex (<b>5</b>) was obtained in which the AcO^-anion acts as a base enough to quantitatively deprotonate the hydrazone. The isatinic hydrazone uses its lactim form in most complexes.</p

The Effects of Length of Residence and Exposure to Violence on Perceptions of Neighborhood Safety in an Urban Sample

Perceptions of neighborhood safety shape the well-being of individuals and communities, affecting neighborhood walkability, associated physical activity behaviors, and health conditions. However, less is known about the factors that determine perceptions of safety. One factor that may affect perceptions of neighborhood safety is the length of time someone has lived in their neighborhood. We use a representative, adult sample of urban low-income residents from the 2015 New Haven Health Survey (n = 1189) to investigate the associations between length of residence (new residents of \u3c 1 year in neighborhood versus longer-term residents of 1 or more years in neighborhood) and perceptions of neighborhood safety (whether feeling unsafe to walk at night). We then examine the potential moderating effect of exposure to neighborhood violence on these associations. We find that the association between length of residence and perceived safety differs by exposure to neighborhood violence. Among those unexposed to neighborhood violence, longer-term neighborhood residents were more likely to feel unsafe compared to new residents (OR = 2.03, 95% CI 1.19, 3.45). Additionally, the effect of exposure to violence on feelings of safety was larger for new residents (OR = 9.10, 95% CI 2.72, 30.44) compared to longer-term residents (OR = 1.88, 95% CI 1.28, 2.77). Our findings suggest that length of residence may have implications for feelings of safety, and that experiences of violence may uniquely contribute to feelings of unsafety among new residents. These findings hold implications for interventions and policy efforts aimed at neighborhood safety improvements through community development, housing, or city urban planning initiatives, particularly for new neighborhood residents or those who experience neighborhood violence

Racial Disparities in Periprosthetic Joint Infections after Primary Total Joint Arthroplasty: A Retrospective Study

In the United States, racial disparities have been observed in complications following total joint arthroplasty (TJA), including readmissions and mortality. It is unclear whether such disparities also exist for periprosthetic joint infection (PJI). The clinical data registry of a large New England hospital system was used to identify patients who underwent TJA between January 2018 and December 2021. The comorbidities were evaluated using the Elixhauser Comorbidity Index (ECI). We used Poisson regression to assess the relationship between PJI and race by estimating cumulative incidence ratios (cIRs) and 95% confidence intervals (CIs). We adjusted for age and sex and examined whether ECI was a mediator using structural equation modeling. The final analytic dataset included 10,018 TJAs in 9681 individuals [mean age (SD) 69 (10)]. The majority (96.5%) of the TJAs were performed in non-Hispanic (NH) White individuals. The incidence of PJI was higher among NH Black individuals (3.1%) compared with NH White individuals (1.6%) [adjusted cIR = 2.12, 95%CI = 1.16–3.89; p = 0.015]. Comorbidities significantly mediated the association between race and PJI, accounting for 26% of the total effect of race on PJI incidence. Interventions that increase access to high-quality treatments for comorbidities before and after TJA may reduce racial disparities in PJI