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1.
Ocul Immunol Inflamm ; : 1-11, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38728578

ABSTRACT

OBJECTIVE: To characterize and describe clinical experience with childhood-onset non-infectious uveitis. STUDY DESIGN: A multicenter retrospective multidisciplinary national web-based registry of 507 patients from 21 hospitals was analyzed. Cases were grouped as immune disease-associated (IMDu), idiopathic (IDIu) or ophthalmologically distinct. Characteristics of juvenile idiopathic arthritis-associated (non-HLA-B27-related) uveitis (JIAu), IDIu, and pars planitis (PP) were compared. RESULTS: IMDu (62.3%) and JIAu (51.9%) predominated in young females; and IDIu (22.7%) and PP (13.6%) in older children, without sex imbalance. Ocular complications occurred in 45.3% of cases (posterior synechiae [28%], cataracts [16%], band keratopathy [14%], ocular hypertension [11%] and cystoid macular edema [10%]) and were associated with synthetic (86%) and biologic (65%) disease-modifying antirheumatic drug (DMARD) use. Subgroups were significantly associated (p < 0.05) with different characteristics. JIAu was typically anterior (98%), insidious (75%), in ANA-positive (69%), young females (82%) with fewer complications (31%), better visual outcomes, and later use of uveitis-effective biologics. In contrast, IDIu was characteristically anterior (87%) or panuveitic (12.1%), with acute onset (60%) and more complications at onset (59%: synechiae [31%] and cataracts [9.6%]) and less DMARD use, while PP is intermediate, and was mostly bilateral (72.5%), persistent (86.5%) and chronic (86.8%), with more complications (70%; mainly posterior segment and cataracts at last visit), impaired visual acuity at onset, and greater systemic (81.2%), subtenon (29.1%) and intravitreal (10.1%) steroid use. CONCLUSION: Prognosis of childhood uveitis has improved in the "biologic era," particularly in JIAu. Early referral and DMARD therapy may reduce steroid use and improve outcomes, especially in PP and IDIu.

2.
Article in English | MEDLINE | ID: mdl-38806311

ABSTRACT

The current demand on health services requires that nurses play a key role, by adapting their competencies to different fields and complexity levels. The approach of situations presented by critically ill patients underpins the need for development of specialised competencies in specific areas such as patient safety, prevention and control of healthcare-associated infections, performance of specific techniques and interventions, autonomous medication management or the use of technology, among others. Spain relies on a specialist training programme that is unique worldwide. Training admission is managed through a contract as a "Resident Nurse Intern" (EIR, Enfermera Interna Residente), provided by regional healthcare services. Only 6 specialities have been established and developed, in an uneven manner and with a short provision of places, annually. Given that the specialization in critical care nursing does not exist, nurses usually self-fund their postgraduate training to enhance their opportunities career development. The development of a speciality for critical care nursing is a priority. The models proposed advocate for creating nursing roles that could cover the systemic gaps through the expansion of their competencies and the introduction of procedures that fit nursing into advanced practice, which could be achieved through Advanced Accreditation Diplomas. Simultaneously, it would be convenient to analyse how and why such a dynamic discipline in some countries became stuck in anachronistic models of the Spanish healthcare system. This analysis might contribute to move forward on the development of areas of improvement in terms of service access and quality of care.

3.
Pulmonology ; 28(1): 28-33, 2022.
Article in English | MEDLINE | ID: mdl-32507497

ABSTRACT

INTRODUCTION: Cytological samples obtained by endobronchial ultrasound (EBUS) are capital for diagnosis, staging and molecular profile in non-small cell lung carcinoma (NSCLC). OBJECTIVE: To assess the success rate of complete, partial and individual of molecular analysis in samples obtained by EBUS-guided transbronchial needle aspiration (TBNA) and/or by oesophageal ultrasound-guided fine needle aspiration with an echobronchoscope (EUS-B-FNA) in patients with NSCLC. METHODS: Prospective study including 90 patients with non-squamous NSCLC, or non-smoking squamous. Cytological samples were classified into two groups. Group 1: PEN membrane slide and/or cell blocks for the determination of mutations of EGFR, KRAS, ERBB2 and BRAF. Group 2: silane coated slides or cell blocks for rearrangements of ALK, ROS1 and MET amplification. RESULTS: The success rate was 78.6% for 4 molecular alterations (EGFR, KRAS, ALK and ROS1), and 44% for 7 determinations. The individual success rate for EGFR was 97%, KRAS 96.3%, ALK 85%, ROS1 82.3%, ERBB2 71.4%, BRAF 67.7% and MET 81.1%. There were no significant differences (p=0.489) in the number of molecular analyses (1-3 vs. 4) in group 1, depending on the types of samples (cell block vs. PEN membrane slide vs. cell block and PEN membrane slide). CONCLUSIONS: In patients with NSCLC, the cytological material obtained by ultrasound-guided needle aspiration is sufficient for individual and partial molecular analysis in the vast majority of cases. Membrane slides such as cell blocks are valid samples for molecular analysis.


Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Endoscopic Ultrasound-Guided Fine Needle Aspiration/methods , Lung Neoplasms/genetics , Aged , Aged, 80 and over , Carcinoma, Non-Small-Cell Lung/diagnosis , Carcinoma, Non-Small-Cell Lung/pathology , DNA Mutational Analysis/methods , ErbB Receptors , Female , Gene Amplification , Humans , Lung Neoplasms/diagnosis , Lung Neoplasms/pathology , Male , Middle Aged , Polymerase Chain Reaction , Prevalence , Prospective Studies , Protein-Tyrosine Kinases/genetics , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins B-raf , Proto-Oncogene Proteins p21(ras) , Receptor Protein-Tyrosine Kinases
5.
Enferm Intensiva (Engl Ed) ; 32(4): 179-180, 2021.
Article in English | MEDLINE | ID: mdl-34732345
6.
Int Nurs Rev ; 68(2): 248-255, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34004014

ABSTRACT

AIM: To survey nurses' opinions about their work conditions at the onset of the COVID-19 pandemic in Spain. BACKGROUND: For the Spanish General Council of Nursing (the Consejo General de Enfermería de España), it was essential to have information on nursing workforce conditions and nurses' preparedness to wear protective measures at the pandemic's onset. The coronavirus outbreak was believed to have started in China and rapidly spread as a global pandemic requiring policies and actions for planning emergency healthcare delivery. METHODS: A cross-sectional survey was conducted online. Data were collected during April 2020 and covered social demography, working conditions, training, availability of personal protective equipment, and nurses' health conditions, including the impact of COVID-19. FINDINGS: From all national territories in Spain, 11 560 registered nurses from different services completed the questionnaire. Findings indicated that the lack of personal protective equipment was a crucial issue, as well as service planning and organization, and 80.2% reported high or very high psychological impact of COVID-19. Alarmingly, 29.5% of the nurses reported COVID-19 symptoms. Of these 23.3% had been tested, and 30.2% were confirmed as being positive to the virus. The nurses deemed proper preparedness for emergencies and disasters as a significant concern. CONCLUSION: Nurses' responses showed evidence of health services deficiencies as a source of damage to their capacity to provide safe patient care and protect themselves and their families' health. The working conditions of the nurses are at critical levels and are unacceptable. The study results provide evidence regarding the necessity of suitable planning and actions being taken to enable safe patient care and safety for nurses. IMPLICATIONS FOR NURSING AND HEALTH POLICY: Our survey gathered nurses' views at the pandemic's onset. The evidence gathered is being used to advise policymakers and nursing organizations to take actions to control public health risks to populations. It is necessary that more investment in growing nursing workforce expertise and health infrastructure for pandemic and epidemic emergencies is provided.


Subject(s)
COVID-19/nursing , Nurses/psychology , Pneumonia, Viral/nursing , Adult , COVID-19/epidemiology , Cross-Sectional Studies , Female , Humans , Male , Pandemics , Personal Protective Equipment , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , SARS-CoV-2 , Spain/epidemiology , Surveys and Questionnaires
8.
Nanoscale ; 11(34): 15871-15880, 2019 Aug 29.
Article in English | MEDLINE | ID: mdl-31414113

ABSTRACT

When a molecule is bound to external electrodes by terminal anchor groups, the latter are of paramount importance in determining the electrical conductance of the resulting molecular junction. Here we explore the electrical properties of a molecule with bidentate anchor groups, namely 4,4'-(1,4-phenylenebis(ethyne-2,1-diyl))bis(pyridin-2-amine), in both large area devices and at the single molecule level. We find an electrical conductance of 0.6 × 10-4G0 and 1.2 × 10-4G0 for the monolayer and for the single molecule, respectively. These values are approximately one order of magnitude higher than those reported for monodentate materials having the same molecular skeleton. A combination of theory and experiments is employed to understand the conductance of monolayer and single molecule electrical junctions featuring this new multidentate anchor group. Our results demonstrate that the molecule has a tilt angle of 30° with respect to the normal to the surface in the monolayer, while the break-off length in the single molecule junction occurs for molecules having a tilt angle estimated as 40°, which would account for the difference in their conductance values per molecule. The bidentate 2-aminepyridine anchor is of general interest as a contact group, since this terminal functionalized aromatic ring favours binding of the adsorbate to the metal contact resulting in enhanced conductance values.

9.
Inorg Chem ; 56(14): 7907-7921, 2017 Jul 17.
Article in English | MEDLINE | ID: mdl-28665126

ABSTRACT

A synthetic strategy has been developed to prepare liquid crystalline cyclotriphosphazenes that have two different types of mesogenic units linked to the same phosphorus atom. Hexachlorocyclotriphosphazene, N3P3Cl6, was reacted with 3 mol of the calamitic unit 4-cyano-4'-hydroxybiphenyl to give a mixture of compounds in which the nongem-trans-trisubstituted derivative N3P3Cl3(OC6H4C6H4{CN}-p)3 was the major product. The substitution of all three chlorine atoms in this nongeminal compound gave rise to the hydroxyl-functional phosphazenes, nongem-trans-N3P3(OC6H4C6H4{CN}-p)3(OC6H4{OH}-p)3 or nongem-trans-N3P3(OC6H4C6H4{CH3}-p)3(OC6H4{OH}-p)3, from which the second mesogenic unit, a polycatenar one, was introduced. The chemical structure of the resulting materials, deduced from spectroscopic and MALDI-TOF techniques, was in accordance with monodisperse, fully functionalized cyclotriphosphazenes. Mesomorphism is highly dependent on the terminal group of the calamitic units, and liquid crystal phases were only detected on the cyano-derivatives. The calamitic or columnar nature of the mesophase depends on the number of alkyl chains of the polycatenar moieties.

10.
Dalton Trans ; 45(20): 8601-13, 2016 May 17.
Article in English | MEDLINE | ID: mdl-27137832

ABSTRACT

The solution/solid state luminescence properties of selected orthometalated palladium complexes have been investigated in parallel with the relevant structural information provided by their X-ray crystal structures and theoretical calculations. Two cyclometalated backbones with different stacking abilities and a selection of bridging O^O, O^N or N^S ligands comprise the series under study, [{Pd(µ-L) (C^N)}2] (C^N = N-phenylpyrazole (Phpz) ; N-benzylideneaniline (Bza) ; L = acetate (Aco) , succinimidate (succ) , phthalimidate (phthal) , 1-methylimidazoline-2 thionate (Smeimid) ), completed with mononuclear [Pd(C^N)(N-pClPhsal)] (N-pClPhsal = chlorophenylsalycilaldiminate) complexes. New compounds , and were synthesized and the X-ray structures of , , , and have been elucidated in order to examine and compare solid-state Pd(C^N)-Pd(C^N) and ligand-ligand interactions with the rest of the series. The molecular structures of the complexes reveal intramolecular PdPd distances between 2.842 and 2.999 Å and π-π and C-Hπ interactions. All complexes studied show emission in the solid state at room temperature and a relationship is observed between emission energy, the nature of the lowest energy excited state, and metal-metal interactions. DFT calculations are undertaken to gain insight into the relationship between the structure and photophysical properties of the complexes.

11.
Arch Soc Esp Oftalmol ; 91(6): 295-7, 2016 Jun.
Article in English, Spanish | MEDLINE | ID: mdl-26896065

ABSTRACT

CLINICAL CASE: An 82-year-old man was admitted to the emergency department complaining of a sudden painless visual loss in his left eye (OS). He was diagnosed with branch retinal artery occlusion (BRAO) with a visible embolus. In 2012, he had a central artery occlusion (CRAO) in his right eye (OD). An embolysis with Nd:YAG laser was attempted, the retinal arterial blood flow was restored completely and the visual field was improved, with no secondary complications. CONCLUSIONS: Nd:YAG laser embolysis is a treatment to be considered in patients with BRAO with a visible embolus. The risks and benefits of the procedure should be evaluated, comparing it with possible permanent loss of visual acuity and other vascular complications caused by BRAO.


Subject(s)
Laser Therapy/methods , Retinal Artery Occlusion/surgery , Vision, Monocular , Aged, 80 and over , Early Diagnosis , Embolectomy , Fluorescein Angiography , Humans , Lasers, Solid-State/therapeutic use , Male , Retinal Artery Occlusion/diagnostic imaging
12.
Tissue Antigens ; 86(5): 373-6, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26373706

ABSTRACT

This study was undertaken to investigate the possible genetic association of functional CTLA4 polymorphisms with susceptibility to non-anterior uveitis. Four hundred and seventeen patients with endogenous non-anterior uveitis and 1517 healthy controls of Spanish Caucasian origin were genotyped for the CTLA4 polymorphisms rs733618, rs5742909 and rs231775, using predesigned TaqMan(©) allele discrimination assays. PLINK software was used for the statistical analyses. No significant associations between the CTLA4 polymorphisms and susceptibility to global non-anterior uveitis were found. It was also the case when the potential association of these genetic variants with the anatomical localization of the disease, such as intermediate, posterior or panuveitis, was assessed. Our results do not support a relevant role of these CTLA4 polymorphisms in the non-anterior uveitis genetic predisposition.


Subject(s)
Genetic Predisposition to Disease , Polymorphism, Genetic , Uveitis/genetics , Adult , CTLA-4 Antigen , Female , Humans , Male , Spain , White People
13.
Soft Matter ; 11(30): 6009-17, 2015 Aug 14.
Article in English | MEDLINE | ID: mdl-26126988

ABSTRACT

In this paper, we present the preparation and properties of some ionic PAMAM derivatives, which combine hydrophilic and lipophilic carboxylic acid chains as counter-ions for all protonable inner and outer amino groups. The amphiphilic nature of the final ionic codendrimers and, hence, their self-assembling features can be modulated by using different ratios between hydrophilic and lipophilic chains. In the bulk, these new materials self-organize into smectic A liquid crystal phases. In water, they self-assemble into different types of nano-objects depending on the molecular composition. The study of the morphology of these nano-structures, their cytotoxicity and their capability to encapsulate a lipophilic anticancer drug are reported herein. Some of these nanoobjects are non-cytotoxic and present good drug trapping ability, which make them interesting nanocarriers for applications in nanotechnology and biomedicine.


Subject(s)
Antineoplastic Agents/chemistry , Dendrimers/chemistry , Drug Delivery Systems , Nanostructures/chemistry , Neoplasms/drug therapy , Antineoplastic Agents/therapeutic use , Dendrimers/chemical synthesis , Dendrimers/therapeutic use , Humans , Hydrophobic and Hydrophilic Interactions , Ions/chemistry , Liquid Crystals/chemistry , Nanostructures/therapeutic use , Nanotechnology , Water/chemistry
14.
Int J Sports Med ; 36(11): 893-9, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26134663

ABSTRACT

The aim of the present study was to assess the reliability, usefulness, validity, age-related differences and responsiveness of a 25- m side-step cutting maneuver test (V-cut test). Fifty young male basketball players performed the V-cut test on 2 occasions separated by 5-7 days to assess test-retest reliability and determine a priori usefulness. Twenty subjects also completed both the L-Run and 505 test to analyze the possible relationships among these 3 tests. Furthermore, 33 players performed the V-cut test 4 times throughout the season to analyze responsiveness. Finally, 53 players (U-14 to U-20) were assessed in the V-cut test to examine the age-related differences. Reliability scores showed high intraclass correlation coefficient (ICC=0.90) and low coefficient of variation (CV=1.4%). The responsiveness of the V-cut test was good, as the typical short- (1.5-1.7%), mid- (1.6-3.1%) and long-term (3.3%) changes in V-cut performance were higher than the CV. Low (r=0.64; CL90%: 0.34; 0.82) to moderate (r=0.76; CL90%: 0.53; 0.88) relationships were found between the V-cut test with the 505 and L-Run test, respectively. Age-related differences analysis showed better V-cut test performance as age increased in adolescent basketball players. The V-cut test is reliable to assess change of direction ability (CODA) and it could be used to monitor CODA in adolescent basketball players.


Subject(s)
Basketball/physiology , Exercise Test/methods , Motor Skills/physiology , Adolescent , Age Factors , Competitive Behavior/physiology , Humans , Male , Physical Education and Training , Reproducibility of Results , Young Adult
15.
Mediators Inflamm ; 2015: 764159, 2015.
Article in English | MEDLINE | ID: mdl-26089603

ABSTRACT

OBJECTIVE: The goals were to isolate and study the genetic susceptibility to retinopathy of prematurity (ROP), as well as the gene-environment interaction established in this disease. METHODS: A retrospective study (2000-2014) was performed about the heritability of retinopathy of prematurity in 257 infants who were born at a gestational age of ≤ 32 weeks. The ROP was studied and treated by a single pediatric ophthalmologist. A binary logistic regression analysis was completed between the presence or absence of ROP and the predictor variables. RESULTS: Data obtained from 38 monozygotic twins, 66 dizygotic twins, and 153 of simple birth were analyzed. The clinical features of the cohorts of monozygotic and dizygotic twins were not significantly different. Genetic factors represented 72.8% of the variability in the stage of ROP, environmental factors 23.08%, and random factors 4.12%. The environmental variables representing the highest risk of ROP were the number of days of tracheal intubation (p < 0.001), postnatal weight gain (p = 0.001), and development of sepsis (p = 0.0014). CONCLUSION: The heritability of ROP was found to be 0.73. The environmental factors regulate and modify the expression of the genetic code.


Subject(s)
Retinopathy of Prematurity/epidemiology , Retinopathy of Prematurity/genetics , Gene-Environment Interaction , Genotype , Humans , Infant, Newborn , Logistic Models , Prospective Studies , Retrospective Studies , Risk Factors
16.
Arch Soc Esp Oftalmol ; 88(6): 231-6, 2013 Jun.
Article in Spanish | MEDLINE | ID: mdl-23726308

ABSTRACT

OBJECTIVE: To prepare a protocol for the treatment of retinopathy of prematurity (ROP) agreed by the majority of Spanish ophthalmologists dedicated to this topic. MATERIAL AND METHOD: A draft of the protocol was produced taking into account the experience of the participants and up to date publications. This draft was corrected by all the ophthalmologists participating in the project, and the final document was agreed by all of them. RESULTS: We present general guidelines as an aid for the treatment of ROP, including treatment criteria, treatment methods, a calendar of action, and follow-up. CONCLUSIONS: It is important to have a common working protocol for the treatment of ROP to improve care and to avoid mistakes. Although individual Hospitals may adapt the protocol to their daily activity, it is recommended that there is a minimal working protocol agreed by most of professionals dedicated to pediatric ophthalmology in Spain.


Subject(s)
Retinopathy of Prematurity/therapy , Clinical Protocols , Humans , Practice Guidelines as Topic , Spain
17.
Arch Soc Esp Oftalmol ; 88(5): 184-8, 2013 May.
Article in English, Spanish | MEDLINE | ID: mdl-23623019

ABSTRACT

OBJECTIVE: To prepare a retinopathy of prematurity (ROP) screening program as agreed by most of Spanish ophthalmologists dedicated to this topic. MATERIALS AND METHODS: A draft of the protocol was produced taking into account the experience of the participants and current publications. This draft was corrected by all the ophthalmologists participating in the project and the final document produced was agreed by all of them. RESULTS: We present general guidelines to help in the screening of ROP, including treatment criteria, treatment methods, and a calendar of action. CONCLUSIONS: It is important to have a common working protocol in the screening of ROP to improve the action and to avoid mistakes. Although individual Hospitals may adapt the protocol to their daily activity, it is recommended that there is a minimal working protocol agreed by most of professionals dedicated to pediatric ophthalmology in Spain.


Subject(s)
Neonatal Screening/standards , Retinopathy of Prematurity/diagnosis , Clinical Protocols , Humans , Infant, Newborn , Practice Guidelines as Topic , Spain
18.
Arch Soc Esp Oftalmol ; 87(4): 119-21, 2012 Apr.
Article in Spanish | MEDLINE | ID: mdl-22482895

ABSTRACT

OBJECTIVE/METHOD: The aim of this study was to assess the importance of immunohistochemical markers in the diagnosis of pigmented conjunctival lesions. Due to the difficulty of making an exact clinical diagnosis, the suspicion of malignancy requires the removal of the lesion and performing a histopathology study in which immunohistochemical markers may help to determine the nature of the lesion. CASES REPORT/DISCUSSION: A case is presented of a 25 year-old woman with a pigmented lesion in the caruncle. It appeared recently and was growing fast with increasing pigmentation. Due to a suspicion of malignancy, the total lesion was removed. The microscopic study revealed cellular alterations which suggested malignancy. However, after carrying out immunohistochemical markers the diagnosis was conjunctival compound nevus.


Subject(s)
Conjunctival Neoplasms/diagnosis , Nevus, Pigmented/diagnosis , Antigens, CD/analysis , Antigens, Differentiation, Myelomonocytic/analysis , Biomarkers, Tumor , Conjunctival Neoplasms/chemistry , Conjunctival Neoplasms/pathology , Conjunctival Neoplasms/surgery , Diagnosis, Differential , Female , Humans , MART-1 Antigen/analysis , Melanoma/diagnosis , Melanoma-Specific Antigens/analysis , Nevus, Pigmented/chemistry , Nevus, Pigmented/pathology , Nevus, Pigmented/surgery , Young Adult , gp100 Melanoma Antigen
19.
Arch. Soc. Esp. Oftalmol ; 87(4): 119-121, abr. 2012. ilus
Article in Spanish | IBECS | ID: ibc-101530

ABSTRACT

Objetivo/Método: Valorar la importancia de los marcadores inmunohistoquímicos para el diagnóstico de certeza de lesiones pigmentadas de la conjuntiva. Debido a la dificultad del diagnóstico clínico exacto, la sospecha de malignidad obliga a realizar una extirpación de la lesión y estudio anatomopatológico en el cual los marcadores inmunohistoquímicos ayudan a determinar la naturaleza de la lesión. Caso clínico/Discusión: Mujer de 25 años que presenta una lesión pigmentada en carúncula de aparición reciente y crecimiento rápido con aumento de la pigmentación. Se sospecha malignidad por lo que se realiza extirpación total de la lesión. El estudio microscópico muestra alteraciones celulares sugerentes de malignidad pero tras realizar marcadores inmunohistoquímicos el diagnóstico es nevus conjuntival compuesto(AU)


Objective/Method: The aim of this study was to assess the importance of immunohistochemical markers in the diagnosis of pigmented conjunctival lesions. Due to the difficulty of making an exact clinical diagnosis, the suspicion of malignancy requires the removal of the lesion and performing a histopathology study in which immunohistochemical markers may help to determine the nature of the lesion. Cases Report/Discussion: A case is presented of a 25 year-old woman with a pigmented lesion in the caruncle. It appeared recently and was growing fast with increasing pigmentation. Due to a suspicion of malignancy, the total lesion was removed. The microscopic study revealed cellular alterations which suggested malignancy. However, after carrying out immunohistochemical markers the diagnosis was conjunctival compound nevus(AU)


Subject(s)
Humans , Immunohistochemistry , Immunohistochemistry/classification , Immunohistochemistry/methods , Immunohistochemistry , Biomarkers, Tumor , Conjunctival Neoplasms/diagnosis , Conjunctival Neoplasms/microbiology , Conjunctival Neoplasms/pathology , Diagnostic Techniques, Ophthalmological , Biomarkers, Tumor/analysis , Nevus/diagnosis , Pigmentation
20.
Dalton Trans ; 40(37): 9504-11, 2011 Oct 07.
Article in English | MEDLINE | ID: mdl-21850339

ABSTRACT

The solid state conformational preferences of ligand 2,4,4-trimethyl-1,5,9-triazacyclododec-1-ene (L1) and its 9-methyl derivative (L2) in transition metal complexes have been determined by a probabilistic method using data retrieved from the Cambridge Structural Database. These macrocyclic compounds, as ligands, tend to adopt a preferential conformation (85% of cases). The ring containing the C=N bond adopts a distorted half-chair conformation, the ring defined by both the N-sp(3) shows a distorted envelope conformation, and the remaining ring exhibits a chair conformation. This conformation corresponds to the enantiomer pair R(N5)S(N9)S(P)/S(N5)R(N9)R(P). Molecular mechanics calculations demonstrate that this is a high energy conformation for the organic molecule, far from the energy minimum. Two other enantiomer pairs are observed in experimental structures. The influence of the coordination on the conformation of the organic ligands has been studied by DFT calculations, and a clear correlation with the geometry of the coordination sphere has been found.


Subject(s)
Coordination Complexes/chemistry , Macrocyclic Compounds/chemistry , Transition Elements/chemistry , Ligands , Models, Molecular , Molecular Conformation
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