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2.
Inorg Chem ; 63(24): 10967-10979, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38832535

RESUMEN

A series of iso-carbamate complexes have been synthesized by the reaction of [SnII(OiPr)2] or [SnII(OtBu)2] with either aryl or alkyl isocyanates, ONC-R (R = 2,4,6-trimethylphenyl (Mes), 2,6-diisopropylphenyl (Dipp), isopropyl (iPr), cyclohexyl (Cy) and tert-butyl (tBu)). In the case of aryl isocyanates, mono-insertion occurs to form structurally characterized complexes [Sn{κ2-N,O-R-NC(OiPr)O}(µ-OiPr)]2 (1: R = Mes, 2: R = Dipp) and [Sn{κ2-N,O-R-NC(OtBu)O}(µ-OtBu)]2 (3: R = Mes, 4: R = Dipp). The complicated solution-state chemistry of these species has been explored using 1H DOSY experiments. In contrast, reactions of tin(II) alkoxides with alkyl isocyanates result in the formation of bis-insertion products [Sn{κ2-N,O-R-NC(OiPr)O}2] (5: R = iPr, and 6: R = Cy) and [Sn{κ2-N,O-R-NC(OtBu)O}2] (7: R = iPr, 8: R = Cy), of which complexes 6-8 have also been structurally characterized. 1H NMR studies show that the reaction of tBu-NCO with either [Sn(OiPr)2] or [Sn(OtBu)2] results in a reversible mono-insertion. Variable-temperature 2D 1H-1H exchange spectroscopy (VT-2D-EXSY) was used to determine the rate of exchange between free tBu-NCO and the coordinated tBu-iso-carbamate ligand for the {OiPr} alkoxide complex, as well as the activation energy (Ea = 92.2 ± 0.8 kJ mol-1), enthalpy (ΔH‡ = 89.4 ± 0.8 kJ mol-1), and entropy (ΔS‡ = 12.6 ± 2.9 J mol-1 K-1) for the process [Sn(OiPr)2] + tBu-NCO ↔ [Sn{κ2-N,O-tBu-NC(OiPr)O}(OiPr)]. Attempts to form Sn(II) alkyl carbonates by the insertion of CO2 into either [Sn(OiPr)2] or [Sn(OtBu)2] proved unsuccessful. However, 119Sn{1H} NMR spectroscopy of the reaction of excess CO2 with [Sn(OiPr)2] reveals the presence of a new Sn(II) species, i.e., [(iPrO)Sn(O2COiPr)], VT-2D-EXSY (1H) of which confirms the reversible alkyl carbonate formation (Ea = 70.3 ± 13.0 kJ mol-1; ΔH‡ = 68.0 ± 1.3 kJ mol-1 and ΔS‡ = -8.07 ± 2.8 J mol-1 K-1).

3.
J Community Psychol ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38932516

RESUMEN

Prior research suggests that culturally aligned, accessible and lower-barrier interventions are well-placed to align with the needs of American Indian and Alaska Native (AI/AN) people with alcohol use disorder (AUD). Taking into account community members' suggestions and the need for physical distancing during the COVID-19 pandemic, our team developed a protocol for virtual Harm Reduction Talking Circles (HaRTC) to incorporate these points. The aims of this 8-week, single-arm pilot were to initially document feasibility, acceptability, and outcomes associated with attendance at virtual HaRTC, which integrates the accessibility of virtual connection, a lower-barrier harm-reduction approach, and a culturally aligned intervention. Participants (N = 51) were AI/AN people with AUD (current or in remission) across 41 Tribal affiliations and 25 US states. After a baseline interview, participants were invited to attend 8, weekly virtual HaRTC sessions. At the baseline, midpoint and post-test assessments, we collected data on virtual HaRTC acceptability, cultural connectedness, quality of life, and alcohol outcomes. Of the 123 people approached, 63% were interested in and consented to participation. Participants attended an average of 2.1 (SD = 2.02) virtual HaRTC sessions, with 64% of participants attending at least one. On a scale from 1 to 10, participants rated the virtual HaRTC as highly acceptable (M = 9.3, SD = 1.9), effective (M = 8.4, SD = 2.9), culturally aligned (M = 9.2, SD = 1.5), helpful (M = 8.8, SD = 1.9), and conducted in a good way (M = 9.8, SD = 0.5). Although the single-arm study design precludes causal inferences, participants evinced statistically significant decreases in days of alcohol use and alcohol-related harm over the three timepoints. Additionally, both sense of spirituality, which is a factor of cultural connectedness, and health-related quality of life increased over time as a function of the number of HaRTC sessions attended. Virtual HaRTC shows initial feasibility and acceptability as a culturally aligned intervention for AI/AN people with AUD. Future randomized controlled trials will provide a test of the efficacy of this approach.

4.
Lancet Respir Med ; 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38679042

RESUMEN

BACKGROUND: Systematic reviews have reported conflicting evidence on whether macrolide antibiotics reduce rates of chronic lung disease of prematurity (CLD) in at-risk preterm infants born at less than 30 weeks' gestation, including in those colonised with pulmonary Ureaplasma spp. Since an adequately powered trial has been lacking, we aimed to assess if the macrolide azithromycin improved survival without the development of physiologically defined moderate or severe CLD in preterm infants. METHODS: AZTEC was a multicentre, double-blind, randomised, placebo-controlled trial conducted in 28 tertiary neonatal intensive care units in the UK. Infants were eligible if they were born at less than 30 weeks' gestation and had received at least 2 h of either non-invasive (continuous positive airway pressure or humidified high flow nasal cannula therapy) or invasive respiratory support (via endotracheal tube) within 72 h of birth. Eligible infants were randomly allocated in a 1:1 ratio using random permuted blocks of four to receive either intravenous azithromycin at 20 mg/kg per day for 3 days followed by 10 mg/kg for 7 days, or to placebo. Allocation was stratified by centre and gestational age at birth (<28 weeks vs ≥28 weeks). Azithromycin and placebo vials were encased in tamper-evident custom cardboard cartons to ensure masking for clinicians, parents, and the research team. The primary outcome was survival without development of physiologically defined moderate or severe CLD at 36 weeks' postmenstrual age. Outcomes and safety were analysed on an intention-to-treat basis (all randomly allocated infants, regardless of any post-randomisation events). The study was registered with ISRCRN (11650227) and is closed. FINDINGS: Infants were recruited between Oct 9, 2019, and March 22, 2022. 799 (53·1%) of 1505 eligible infants underwent random allocation; three infants were withdrawn, including consent to use their data, leaving 796 infants for analysis. Survival without moderate or severe CLD occurred in 166 (42%) of 394 infants in the intervention group and 179 (45%) of 402 in the placebo group (three-level adjusted OR [aOR] 0·84, 95% CI 0·55-1·29, p=0·43). Pulmonary Ureaplasma spp colonisation did not influence treatment effect. Overall, seven serious adverse events were reported for the azithromycin group (five graded as severe, two as moderate), and six serious adverse events were reported in the placebo group (two severe, two moderate, and two mild), as assessed by the local principal investigators. INTERPRETATION: Since prophylactic use of azithromycin did not improve survival without development of physiologically-defined CLD, regardless of Ureaplasma spp colonisation, it cannot be recommended in clinical practice. FUNDING: UK National Institute for Health and Care Research.

7.
Infect Control Hosp Epidemiol ; 45(6): 785-787, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38329022

RESUMEN

In recognition of an increasing number of high-consequence infectious disease events, a group of subject-matter experts identified core safety principles that can be applied across all donning and doffing protocols for personal protective equipment.


Asunto(s)
Equipo de Protección Personal , Humanos , Control de Infecciones/métodos , Infección Hospitalaria/prevención & control , Transmisión de Enfermedad Infecciosa de Paciente a Profesional/prevención & control
8.
Cancer Med ; 13(3): e6925, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38214042

RESUMEN

OBJECTIVE: To collate and critically review international evidence on the direct health system costs of children and adolescents and young adults (AYA) with cancer. METHODS: We conducted searches in PubMed, MEDLINE, CINAHL, and Scopus. Articles were limited to studies involving people aged 0-39 years at cancer diagnosis and published from 2012 to 2022. Two reviewers screened the articles and evaluated the studies using the Consolidated Health Economic Evaluation Reporting Standards checklist. The reviewers synthesized the findings using a narrative approach and presented the costs in 2022 US dollars for comparability. RESULTS: Overall, the mean healthcare costs for all cancers in the 5 years post diagnosis ranged from US$36,670 among children in Korea to US$127,946 among AYA in the USA. During the first year, the mean costs among children 0-14 years ranged from US$34,953 in Chile to over US$130,000 in Canada. These were higher than the costs for AYA, estimated at US$61,855 in Canada. At the end of life, the mean costs were estimated at over US$300,000 among children and US$235,265 among adolescents in Canada. Leukemia was the most expensive cancer type, estimated at US$50,133 in Chile, to US$152,533 among children in Canada. Overall, more than a third of the total cost is related to hospitalizations. All the included studies were of good quality. CONCLUSIONS: Healthcare costs associated with cancer are substantial among children, and AYA. More research is needed on the cost of cancer in low- and middle-income countries and harmonization of costs across countries.


Asunto(s)
Leucemia , Neoplasias , Niño , Adolescente , Humanos , Adulto Joven , Neoplasias/epidemiología , Neoplasias/terapia , Costos de la Atención en Salud , Canadá , Lista de Verificación
9.
Res Nurs Health ; 47(2): 234-241, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38281085

RESUMEN

The purpose of this study was to examine the impact of a culturally based intervention, the Intertribal Talking Circle program, compared to a standard alcohol and drug abuse education, the Be A Winner program. Community-based participatory research was used to implement a two-condition, quasi-experimental study. The sample included 540 Native American youth ages 10-12 years old from three tribal areas in the United States. Data were collected at baseline, 6 and 12-months post-intervention for both the intervention and control groups using demographic, cultural identity, alcohol use, and drug use questionnaires. Regression models evaluated participants' improvement in decreasing alcohol and drug use and increasing cultural identity. Findings revealed that alcohol and drug use decreased more significantly among youth who participated in the Intertribal Talking Circle (ITC) intervention program than youth who participated in a standard alcohol and drug abuse education Be A Winner (BAW) program. Cultural identity also increased more significantly among participants who completed the Talking Circle intervention program. Native American youth ages 10-12 years old respond positively to a culturally based intervention for the reduction of alcohol and drug use. The findings highlight the importance of cultural values and identity and their significance in preventing and reducing alcohol and drug use among Native American youth.


Asunto(s)
Indio Americano o Nativo de Alaska , Trastornos Relacionados con Sustancias , Niño , Humanos , Educación en Salud , Trastornos Relacionados con Sustancias/prevención & control , Encuestas y Cuestionarios , Estados Unidos , Asistencia Sanitaria Culturalmente Competente
11.
Qual Life Res ; 33(3): 679-689, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38019323

RESUMEN

PURPOSE: Psychosexual distress is known to be a common complication of treatment for gynaecological cancer (GC), affecting the sexual quality of life (SQoL) for an increasing number of young gynaecological cancer survivors (YGCS). The SQoL in YGCS study aimed to identify strategies that are acceptable and helpful to YGCS in protecting and improving SQoL, using a salutogenic approach. METHODS: A qualitative study was undertaken with young women aged 18-45 and pre- or perimenopausal at diagnosis. Semi-structured interviews were conducted on Zoom and a thematic analysis of transcripts was completed in NVivo. RESULTS: Fifteen interviews with YGCS revealed three themes for strategy development: psychosexual education, psychosocial support, and healthcare policy and strategy to establish SQoL as standard care in gynaecologic oncology. CONCLUSION: The strategies put forward by YGCS showed the need for a holistic, patient-centric, and multidisciplinary approach to SQoL. A better understanding of the strategies acceptable to YGCS, including the importance of using a trauma-informed approach to communication and care, can help healthcare providers play a vital role in protecting and improving SQoL.


Asunto(s)
Supervivientes de Cáncer , Neoplasias de los Genitales Femeninos , Humanos , Femenino , Neoplasias de los Genitales Femeninos/psicología , Calidad de Vida/psicología , Conducta Sexual/psicología , Supervivientes de Cáncer/psicología
12.
Anal Chem ; 95(46): 16801-16809, 2023 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-37931004

RESUMEN

1H NMR spectroscopic studies using BINOL as a chiral solvating agent (CSA) for a scalemic sulfiniminoboronic acid (SIBA) have revealed concentration- and enantiopurity-dependent variations in the chemical shifts of diagnostic imine protons used to determine enantiopurity levels. 11B/15N NMR spectroscopic studies and X-ray structural investigations revealed that unlike other iminoboronate species, BINOL-SIBA assemblies do not contain N-B coordination bonds, with 1H NMR NOESY experiments indicating that intermolecular H-bonding networks between BINOL and the SIBA analyte are responsible for these variations. These effects can lead to diastereomeric signal overlap at certain er values that could potentially lead to enantiopurity/configuration misassignments. Consequently, it is recommended that hydrogen-bonding-CSA-based 1H NMR protocols should be repeated using both CSA enantiomers to ensure that any concentration- and/or er-dependent variations in diagnostic chemical shifts are accounted for when determining the enantiopurity of a scalemic analyte.

13.
ACS Appl Mater Interfaces ; 15(36): 42369-42377, 2023 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-37638824

RESUMEN

Molecularly rigid polymers with internal charges (positive charges induced by amine methylation) allow electroosmotic water flow to be tuned by adjusting the charge density (the degree of methylation). Here, a microporous polyamine (PIM-EA-TB) is methylated to give a molecularly rigid anion conductor. The electroosmotic drag coefficient (the number of water molecules transported per anion) is shown to increase with a lower degree of methylation. Net water transport (without charge flow) in a coupled anionic diode circuit is demonstrated based on combining low and high electroosmotic drag coefficient materials. The AC-electricity-driven net process offers water transport (or transport of other neutral species, e.g., drugs) with net zero ion transport and without driver electrode side reactions.

14.
Qual Health Res ; 33(10): 897-910, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37420336

RESUMEN

The life-history narratives of 10 Mexican American men with mobility limitations, age 55-77 years (mean = 63.8, SD = 5.8), were explored using a qualitatively driven, life-history mixed-methods study to understand perceptions of mobility limitations over the life course. Within that methodological and paradigmatic framework, conceptualizations of alterity and masculinity guided interpretation of data. Through an iterative, thematic analysis, we detail the way the men's lives were influenced by growing familial responsibility with age. Quantitative data were integrated into themes of narrative inheritance, family, and masculinity. It was posited that masculinity with mobility limitations shaped and was shaped by ethnic identity and responsibility. This has implications for understanding the experience of Mexican American men over the life course.


Asunto(s)
Americanos Mexicanos , Limitación de la Movilidad , Masculino , Humanos , Persona de Mediana Edad , Anciano , Hombres , Masculinidad , Acontecimientos que Cambian la Vida
15.
Am J Infect Control ; 51(12): 1384-1391, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37182761

RESUMEN

BACKGROUND: Heat strain and dehydration can affect an individual's physical and mental performance. The purpose of this review was to examine the literature for the impact of heat strain on health care workers (HCWs) who care for patients with high-consequence infectious diseases (HCIDs) while wearing personal protective equipment (PPE), discuss the risks of impaired safety caused by heat strain and dehydration in HCID environments, identify attempts to combat PPE-related heat strain, recognize limitations, and provide suggestions for further research. METHODS: A literature search was performed in PubMed or MEDLINE and Google Scholar. Authors screened abstracts for inclusion criteria and reviewed articles if the abstracts were considered to include information relevant to the aim. RESULTS: The search terms yielded 30 articles that were sorted based on environment setting, physiological impact, and interventions. DISCUSSION: The safety of the HCWs and patients can be enhanced through the development and usage of cooler, more comfortable PPE materials and ensembles to help slow the rate of dehydration and support the regulation of core body temperature. CONCLUSIONS: Heat strain caused by wearing PPE is an occupational health concern for HCWs in the high-risk environment, that is, HCID care. Future studies are needed to develop innovative PPE ensembles that can reduce heat strain and improve well-being.


Asunto(s)
Enfermedades Transmisibles , Deshidratación , Humanos , Equipo de Protección Personal , Personal de Salud , Calor
16.
Air Med J ; 42(3): 201-209, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37150575

RESUMEN

OBJECTIVE: In 2019, our team conducted a literature review of air medical evacuation high-level containment transport (AE-HLCT) of patients infected with high-consequence pathogens. Since that publication, the coronavirus disease 2019 (COVID-19) pandemic has resulted in numerous air medical evacuations. We re-examined the new literature associated with AE-HLCTs to determine new innovations developed as a result of the pandemic. METHODS: A literature search was performed in PubMed/MEDLINE from February 2019 to October 2021. The authors screened abstracts for the inclusion criteria and reviewed full articles if the abstract was relevant to the aim. RESULTS: Our search criteria yielded 19 publications. Many of the early transports of patients with COVID-19 used established protocols for AE-HLCT, which were built from the most recent transports of patients with Ebola virus disease. Innovations from the identified articles are subdivided into preflight considerations, in-flight operations, and postflight operations. CONCLUSION: Lessons gleaned from AE-HLCTs of patients with COVID-19 in the early weeks of the pandemic, when little was known about transmission or the severity of the novel disease, have advanced the field of AE-HLCT. Teams that had never conducted such transports now have experience and processes. However, more research into AE-HLCT is needed, including research related to single-patient portable isolation units as well as containerized/multipatient transportation systems.


Asunto(s)
Ambulancias Aéreas , COVID-19 , Humanos , Pandemias , Aislamiento de Pacientes
17.
J Community Psychol ; 51(7): 2581-2591, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37027390

RESUMEN

Native American young adults residing in urban communities are particularly vulnerable to substance use. After leaving high school, the pressures and stress of continuing education, finding employment, and the responsibilities related to family and tribal community obligations predispose these young adults to substance use. This study used a pre/post test design to evaluate a cultural-based Talking Circle intervention for the prevention of substance use among urban Native American young adults, ages 18-24. Three measures were used that included the Native-Reliance Questionnaire, the Indigenous-Global Assessment of Individual Needs (I-GAIN) Substance Use Scale, and the Patient Health Questionnaire (PHQ-9) measure for severity of depression. Findings revealed that participants demonstrated a higher sense of Native-Reliance, decrease in substance use, and a decrease in the PHQ-9 depressions scores from baseline to 6-month postintervention. These findings validate the importance of cultural-based interventions for the prevention of substance use among urban Native American young adults.


Asunto(s)
Indígenas Norteamericanos , Trastornos Relacionados con Sustancias , Humanos , Adulto Joven , Conducta Social , Trastornos Relacionados con Sustancias/prevención & control , Encuestas y Cuestionarios
18.
Chemistry ; 29(38): e202300215, 2023 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-36946535

RESUMEN

Sensitivity in FlowNMR spectroscopy for reaction monitoring often suffers from low levels of pre-magnetisation due to limited residence times of the sample in the magnetic field. While this in-flow effect is tolerable for high sensitivity nuclei such as 1 H and 19 F, it significantly reduces the signal-to-noise ratio in 31 P and 13 C spectra, making FlowNMR impractical for low sensititvity nuclei at low concentrations. Paramagnetic relaxation agents (PRAs), which enhance polarisation and spin-lattice relaxation, could eliminate the adverse in-flow effect and improve the signal-to-noise ratio. Herein, [Co(acac)3 ], [Mn(acac)3 ], [Fe(acac)3 ], [Cr(acac)3 ], [Ni(acac)2 ]3, [Gd(tmhd)3 ] and [Cr(tmhd)3 ] are investigated for their effectiveness in improving signal intensity per unit time in FlowNMR applications under the additional constraint of chemical inertness towards catalytically active transition metal complexes. High-spin Cr(III) acetylacetonates emerged as the most effective compounds, successfully reducing 31 P T1 values four- to five-fold at PRA concentrations as low as 10 mM without causing adverse line broadening. Whereas [Cr(acac)3 ] showed signs of chemical reactivity with a mixture of triphenylphosphine, triphenylphosphine oxide and triphenylphosphate over the course of several hours at 80° C, the bulkier [Cr(tmhd)3 ] was stable and equally effective as a PRA under these conditions. Compatibility with a range of representative transition metal complexes often used in homogeneous catalysis has been investigated, and application of [Cr(tmhd)3 ] in significantly improving 1 H and 31 P{1 H} FlowNMR data quality in a Rh-catalysed hydroformylation reaction has been demonstrated. With the PRA added, 13 C relaxation times were reduced more than six-fold, allowing quantitative reaction monitoring of substrate consumption and product formation by 13 C{1 H} FlowNMR spectroscopy at natural abundance.


Asunto(s)
Complejos de Coordinación , Elementos de Transición , Complejos de Coordinación/química , Espectroscopía de Resonancia Magnética/métodos
19.
Qual Life Res ; 32(7): 2107-2115, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36947327

RESUMEN

PURPOSE: The impact of cancer diagnosis and treatment on sexual quality of life (SQoL) is a significant and often neglected issue in the treatment and survivorship period of young gynaecological cancer survivors (YGCS). This study sought to explore women's lived experiences to understand how to protect and improve SQoL. METHODS: A qualitative study with women aged 18-45 and pre- or perimenopausal at diagnosis (n = 15). A thematic analysis was performed in NVivo. Participants also completed a pre-interview questionnaire and The Female Sexual Distress Scale-Revised (FSDS-R). RESULTS: YGCS experienced high psychosexual distress. Notably, seven themes were identified: adjustment, confidence, fear, loss, shame, trauma, and communication. Gynaecological cancer (GC) treatment interfered with everyday life and had a long-term impact on mental, physical, and emotional health, with many reporting an altered sense of self, body image and sexual identity. Single women felt vulnerable in new relationships, while partnered women reported low sexual desire and guilt about sexual difficulties. Open communication, emotional intimacy, and an acceptance of the 'new normal' buffered the trauma of cancer and were vital to relationship satisfaction. Lastly, absent, or blunt patient-clinician communication contributed to psychosexual distress. CONCLUSION: GC interferes with sexual function, partner relationships, psychosexual wellbeing, and quality of life. A better understanding of the lived experiences of YGCS can help healthcare providers to adopt a holistic, patient-centric, and multidisciplinary approach to SQoL. YGCS want psychosexual communication and support, across all stages of treatment and care. Healthcare providers should initiate and normalise conversations on the impact of treatment on SQoL.


Asunto(s)
Supervivientes de Cáncer , Neoplasias , Femenino , Humanos , Calidad de Vida/psicología , Conducta Sexual/psicología , Emociones
20.
Inorg Chem ; 62(12): 4770-4785, 2023 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-36916880

RESUMEN

A family of zinc phosphate complexes supported by nitrogen donor-base ligands have been synthesized, and their molecular structures were identified in both the solid (X-ray crystallography) and solution state (DOSY NMR spectroscopy). [Zn{O2P(OPh)2}2]∞ (1), formed from the reaction of Zn[N(SiMe3)2]2 with HO(O)P(OPh)2 coordinates to donor-base ligands, i.e., pyridine (Py), 4-methylpyridine (4-MePy), 2,2-bipyridine (bipy), tetramethylethylenediamine (TMEDA), pentamethyldiethylenetriamine (PMDETA), and 1,3,5-trimethyl-1,3,5-triazacyclohexane (Me3-TAC), to produce polymeric 1D structures, [(Py)2Zn{O2P(OPh)2}2]∞ (2) and [(4-MePy)2Zn{O2P(OPh)2}2]∞ (3), the bimetalic systems, [(Bipy)Zn{O2P(OPh)2}2]2 (4), [(TMEDA)Zn{O2P(OPh)2}2]2 (5), and [(Me3-TAC)Zn{O2P(OPh)2}2]2 (7), as well as a mono-nuclear zinc bis-diphenylphosphate complex, [(PMDETA)Zn{O2P(OPh)2}2] (6). 1H NMR DOSY has been used to calculate averaged molecular weights of the species. Studies are consistent with the disassembly of polymeric 3 into the bimetallic species [(Me-Py)2·Zn2{O2P(OPh)2}4], where the Me-Py ligand is in rapid exchange with free Me-Py in solution. Further 1H DOSY NMR studies of 4 and 5 reveal that dissolution of the complex results in a monomer dimer equilibrium, i.e., [(Bipy)Zn{O2P(OPh)2}2]2 ⇆ 2[(Bipy)Zn{O2P(OPh)2}2] and [(TMEDA)Zn{O2P(OPh)2}2]2 ⇆ 2[(TMEDA)Zn{O2P(OPh)2}2], respectively, in which the equilibria lie toward formation of the monomer. As part of our studies, variable temperature 1H DOSY experiments (223 to 313 K) were performed upon 5 in d8-tol, which allowed us to approximate the enthalpy [ΔH = -43.2 kJ mol-1 (±3.79)], entropy [ΔS = 109 J mol-1 K-1 (±13.9)], and approximate Gibbs free energy [ΔG = 75.6 kJ mol-1 (±5.62) at 293 K)] of monomer-dimer equilibria. While complex 6 is shown to maintain its monomeric solid-state structure, 1H DOSY experiments of 7 at 298 K reveal two separate normalized diffusion coefficients consistent with the presence of the bimetallic species [(TAC)2-xZn2{O2P(OPh)2}4], (x = 1 or 0) and free TAC ligand.

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