Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
Sci Rep ; 13(1): 9121, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37277417

RESUMO

During the COVID-19 pandemic in Senegal, contact tracing was done to identify transmission clusters, their analysis allowed to understand their dynamics and evolution. In this study, we used information from the surveillance data and phone interviews to construct, represent and analyze COVID-19 transmission clusters from March 2, 2020, to May 31, 2021. In total, 114,040 samples were tested and 2153 transmission clusters identified. A maximum of 7 generations of secondary infections were noted. Clusters had an average of 29.58 members and 7.63 infected among them; their average duration was 27.95 days. Most of the clusters (77.3%) are concentrated in Dakar, capital city of Senegal. The 29 cases identified as super-spreaders, i.e., the indexes that had the most positive contacts, showed few symptoms or were asymptomatic. Deepest transmission clusters are those with the highest percentage of asymptomatic members. The correlation between proportion of asymptomatic and degree of transmission clusters showed that asymptomatic strongly contributed to the continuity of transmission within clusters. During this pandemic, all the efforts towards epidemiological investigations, active case-contact detection, allowed to identify in a short delay growing clusters and help response teams to mitigate the spread of the disease.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/epidemiologia , Busca de Comunicante , Pandemias , Senegal/epidemiologia
2.
J Med Virol ; 95(1): e28347, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36424699

RESUMO

Globally, 390 million people are at risk of dengue infection and over the past 50 years, the virus incidence increased thirty-fold. In Senegal, an unprecedented occurrence of outbreaks and sporadic cases have been noticed since 2017. In October 2018, an outbreak of Dengue virus 2 (DENV-2) was reported in the north of Senegal affecting multiple areas including Saint-Louis, Richard Toll, and Rosso which are located at the border with Mauritania. Of these 173 blood specimen samples collected from patients, 27 were positive for dengue by quantitative reverse transcription PCR (qRT-PCR), and eight were serologically confirmed to be positive for DENV immunoglobulin M (IgM). Serotyping using qRT-PCR reveals that isolates were positive for DENV-2. A subset of DENV-2 positive samples was selected and subjected to whole-genome sequencing followed by phylogenetic analysis. Analysis of six nearly complete genome sequences revealed that the isolates belong to the cosmopolitan genotype and are closely related to the Mauritanian strains detected between 2017 and 2018 and those detected in many West African countries such as Burkina Faso or Cote d'Ivoire. Our results suggest a transboundary circulation of the DENV-2 cosmopolitan genotype between Senegal and Mauritania and call for a need for coordinated surveillance of arboviruses between these two countries. Interestingly, a high level of homology between West African isolates highlights endemicity and calls for the set-up of subregional viral genomic surveillance which will lead to a better understanding of viral dynamics, transmission, and spread across Africa.


Assuntos
Vírus da Dengue , Dengue , Humanos , Dengue/epidemiologia , Senegal/epidemiologia , Filogenia , Surtos de Doenças , Genótipo , Burkina Faso , Sorogrupo
3.
Front Public Health ; 11: 1292435, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38249384

RESUMO

Surveillance to better detect and respond to new pathogens remains a major challenge for global public health. The Pasteur Network recently held a brainstorming workshop located in Cameroon attended by Pasteur epidemiological teams from Niger, Central African Republic (CAR), Cameroon, Senegal, and Madagascar to discuss how the Pasteur Network in Africa could use the lessons of COVID-19 to set-up a pilot sentinel surveillance scheme given its expertise and involvement during the pandemic. The possibility of coupling sentinel syndromic and biological surveillance already implemented for influenza surveillance with the recent sequencing capacity put in place by the AFROSCREEN program prompted us to consider strengthening surveillance tools to target "Pathogen X" detection in Africa. The perspective project provided by the Pasteur Network teams and shared with other partners of the AFROSCREEN program will target strengthening of the diagnosis of severe acute respiratory infections (IRAS) and the surveillance of IRAS, the evaluation of the impact of SARS-CoV-2 on the epidemiology of IRAS, and the addition of the detection of new pathogens, called "Pathogen X," based on sequencing capacity and epidemiological criteria from One Health approaches.


Assuntos
Infecções Respiratórias , Vigilância de Evento Sentinela , Humanos , África , População Negra , COVID-19/epidemiologia , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/etiologia , Madagáscar/epidemiologia , Camarões/epidemiologia , População Africana , Níger/epidemiologia , República Centro-Africana/epidemiologia , Senegal/epidemiologia
4.
Acta Crystallogr E Crystallogr Commun ; 78(Pt 10): 1072-1076, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36250123

RESUMO

This article reports a practical synthesis of tert-butyl acetyl-carbamate, C7H13NO3, from N-Boc-thio-acetamide and the study of its crystal structure. The reaction proceeds in the presence of natural phosphate as a catalyst, with excellent yield, simple workup and benign environment. The crystal structure was refined using a transferred multipolar atom model. In the crystal, symmetrical pairs of strong N-H⋯O hydrogen bonds connect the mol-ecules into dimers with an R 2 2(8) ring motif. The inter-actions between neighbouring dimers are mostly van der Waals, between hydro-phobic methyl groups. Hirshfeld surface analysis shows the major contributions to the crystal packing are from H⋯H (42.6%) and O⋯H (26.7%) contacts.

6.
Glob Health Sci Pract ; 10(5)2022 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-36316144

RESUMO

In 2016, the Gavi Cold Chain Equipment Optimization Platform (CCEOP) was approved and launched in recognition of the fact that functional cold chain equipment (CCE) is essential to strengthening vaccine supply chains and ultimately achieving Gavi's immunization equity and coverage goals. Through CCEOP, Gavi committed to investing US$250 million between 2016 and 2021 to commission CCE in more than 63,000 facilities to upgrade and expand their CCE footprint while stimulating the market to provide affordable, technologically advanced, and accessible equipment. We present case studies from Guinea and Kenya, both of which received CCEOP support, that highlight 2 ways for countries to prioritize investments and implement activities through a large funding and support mechanism. The studies explore the different ways that each country implemented CCEOP and consider how aspects of leadership and technical capacity influence country priorities and results. They also uncover key lessons on sustainability of a large immunization supply chain effort. The experiences of Guinea and Kenya can help other countries embarking on similarly large health system interventions, especially related to supply chain strengthening and immunization programs. In particular, these experiences offer important lessons in leadership, processes and systems, country ownership, technical capacity, and sustainability.


Assuntos
Cooperação Internacional , Refrigeração , Humanos , Guiné , Quênia , Programas de Imunização
7.
PLoS One ; 17(9): e0274783, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36126041

RESUMO

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) pandemic has spread from China to the rest of the world. Africa seems less impacted with lower number of cases and deaths than other continents. Senegal recorded its first case on March 2, 2020. We present here data collected from March 2 to October 31, 2020 in Senegal. METHODS: Socio-demographic, epidemiological, clinical and virological information were collected on suspected cases. To determine factors associated with diagnosed infection, symptomatic disease and death, multivariable binary logistic regression and log binomial models were used. Epidemiological parameters such as the reproduction number and growth rate were estimated. RESULTS: 67,608 suspected cases were tested by the IPD laboratories (13,031 positive and 54,577 negative). All age categories were associated with SARS-CoV-2 infection, but also patients having diabetes or hypertension or other cardiovascular diseases. With diagnosed infection, patients over 65 years and those with hypertension and cardiovascular disease and diabetes were highly associated with death. Patients with co-morbidities were associated with symptomatic disease, but only the under 15 years were not associated with. Among infected, 27.67% were asymptomatic (40.9% when contacts were systematically tested; 12.11% when only symptomatic or high-risk contacts were tested). Less than 15 years-old were mostly asymptomatic (63.2%). Dakar accounted for 81.4% of confirmed cases. The estimated mean serial interval was 5.57 (± 5.14) days. The average reproduction number was estimated at 1.161 (95%CI: 1.159-1.162), the growth rate was 0.031 (95%CI: 0.028-0.034) per day. CONCLUSIONS: Our findings indicated that factors associated with symptomatic COVID-19 and death are advanced age (over 65 years-old) and comorbidities such as diabetes and hypertension and cardiovascular disease.


Assuntos
COVID-19 , Doenças Cardiovasculares , Diabetes Mellitus , Hipertensão , Adolescente , Idoso , COVID-19/epidemiologia , Diabetes Mellitus/epidemiologia , Humanos , Hipertensão/epidemiologia , Pandemias , SARS-CoV-2 , Senegal/epidemiologia
8.
BMJ Glob Health ; 7(2)2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35193893

RESUMO

BACKGROUND: When vaccines against the novel COVID-19 were available in Senegal, many questions were raised. How long should non-pharmaceutical interventions (NPIs) be maintained during vaccination roll-out? What are the best vaccination strategies? METHODS: In this study, we used an age-structured dynamic mathematical model. This model uses parameters based on SARS-CoV-2 virus, information on different types of NPIs, epidemiological and demographic data, some parameters relating to hospitalisations and vaccination in Senegal. RESULTS: In all scenarios explored, the model predicts a larger third epidemic wave of COVID-19 in terms of new cases and deaths than the previous waves. In a context of limited vaccine supply, vaccination alone will not be sufficient to control the epidemic, and the continuation of NPIs is necessary to flatten the epidemic curve. Assuming 20% of the population have been vaccinated, the optimal period to relax NPIs would be a few days from the last peak. Regarding the prioritisation of age groups to be vaccinated, the model shows that it is better to vaccinate individuals aged 5-60 years and not just the elderly (over 60 years) and those in high-risk groups. This strategy could be more cost-effective for the government, as it would reduce the high costs associated with hospitalisation. In terms of vaccine distribution, the optimal strategy would be to allocate full dose to the elderly. If vaccine doses are limited, half dose followed by full dose would be sufficient for people under 40 years because whether they receive half or full dose, the reduction in hospitalisations would be similar and their death-to-case ratio is very low. CONCLUSIONS: This study could be presented as a decision support tool to help devise strategies to control the COVID-19 pandemic and help the Ministry of Health to better manage and allocate the available vaccine doses.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Humanos , Pessoa de Meia-Idade , Pandemias , SARS-CoV-2 , Senegal/epidemiologia , Vacinação , Adulto Jovem
9.
Acta Crystallogr E Crystallogr Commun ; 77(Pt 7): 708-713, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34513016

RESUMO

The title mol-ecular structure, namely, di-aqua-tris-(µ3-1,3-bis-{[1-(2-oxidophen-yl)ethyl-idene]amino}-propan-2-olato)-µ3-hydroxido-dinitrato-hexa-copper(II) ethanol tris-olvate, [Cu6(C19H19N2O3)3(NO3)2(OH)(H2O)2]·3C2H5OH, corres-ponds to a non-symmetric hexa-nuclear copper complex. The complex exhibits one core in which three CuII metal centres are mutually inter-connected, two by two, via three phenolato oxygen anions acting in a µ2-mode. These three copper cations are inter-connected in a µ3-mode by one hydroxyl group. An open-cube structure is generated in which each of the CuII cations of the three CuO4N units is connected by two µ2-O anions from phenolate groups and one µ3-O atom from a hy-droxy anion. Each of the three penta-coordinated CuII cations situated in the open-cube unit has a distorted NO4 square-pyramidal environment. Each of these three CuII centres is inter-connected with another CuII cation via one enolate O atom in µ2-mode, yielding one CuNO4 unit and two CuNO3 units. The penta-coordinated CuII atom has a distorted square-pyramidal environment while the two tetra-coordinated copper(II) cations are situated in a square-planar environment. A series of intra-molecular O-H⋯O hydrogen bonds are observed. In the crystal, the units are connected two by two by inter-molecular C-H⋯O and O-H⋯O hydrogen bonds, thus forming sheets parallel to the ac plane.

10.
J Trop Med ; 2021: 8817987, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33868410

RESUMO

Dengue virus (DENV) is the most prevalent arboviral threat worldwide. This virus belonging to genus Flavivirus, Flaviviridae family, is responsible for a wide spectrum of clinical manifestations, ranging from asymptomatic or mild febrile illness (dengue fever) to life-threatening infections (severe dengue). Many sporadic cases and outbreaks have occurred in Senegal since 1970. Nevertheless, this article describes a field investigation of suspected dengue cases, between 05 September 2017 and 17 December 2017 made possible by the deployment of a Mobile Biosafety Laboratory (MBS-Lab). Overall, 960 human sera were collected and tested in the field for the presence of viral RNA by real-time RT-PCR. Serotyping, sequencing of complete E gene, and phylogenetic analysis were also performed. Out of 960 suspected cases, 131 were confirmed dengue cases. The majority of confirmed cases were from Louga community. Serotyping revealed two serotypes, Dengue 1 (100/104; 96, 15%) and Dengue 2 (04/104; 3, 84%). Phylogenetic analysis of the sequences obtained indicated that the Dengue 1 strain was closely related to strains isolated, respectively, in Singapore (Asia) in 2013 (KX380803.1) outbreak and it cocirculated with a Dengue 2 strain closely related to strains from a Burkina Faso dengue outbreak in 2016 (KY62776.1). Our results showed the co-circulation of two dengue virus serotypes during a single outbreak in a short time period. This co-circulation highlighted the need to improve surveillance in order to prevent future potential severe dengue cases through antibody-dependent enhancement (ADE). Interestingly, it also proved the reliability and usefulness of the MBS-Lab for expedient outbreak response at the point of need, which allows early cases management.

11.
Nanomaterials (Basel) ; 10(2)2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32075285

RESUMO

Cobalt nano-rods with the hexagonal close-packed (hcp) structure were prepared by reduction of the long-chain carboxylate Co (II) precursor in polyol. The application of an external magnetic field (µ0H = 1.25 T) during the nucleation and growth steps resulted in a noticeable modification of the mean aspect ratio (length/diameter) of the particles. The particle morphology was also modified as the nano-rods did not exhibit conical heads at their extremities anymore, which are observed for particles prepared without application of an external magnetic field. Besides, the stacking faults density along the c axis of the hcp structure in the cobalt nano-rods has been found to decrease with the increase in the applied magnetic field. The coercive field of randomly oriented nano-rods increased with the aspect ratio, showing the highest value (i.e., 5.8 kOe at 300 K) for the cobalt nano-rods obtained under the highest applied magnetic field. For partially oriented Co nano-rods in toluene solution, the magnetic properties were significantly enhanced with a coercive field of 7.2 kOe at 140 K, while the magnetization saturation reached 92% of the bulk. The MR/MS value was about 0.8, indicating a good orientation of the anisotropic particles relative to each other, making them suitable for the preparation of permanent magnets via a bottom-up approach.

12.
Acta Crystallogr E Crystallogr Commun ; 75(Pt 7): 1069-1075, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31392027

RESUMO

Two CuII complexes [Cu(C14H13N4O2)Cl] n , I, and [Cu4(C8H10NO2)4Cl4] n , II, have been synthesized. In the structure of the mononuclear complex I, each ligand is coordinated to two metal centers. The basal plane around the CuII cation is formed by one chloride anion, one oxygen atom, one imino and one pyridine nitro-gen atom. The apical position of the distorted square-pyramidal geometry is occupied by a pyridine nitro-gen atom from a neighbouring unit, leading to infinite one-dimensional polymeric chains along the b-axis direction. Each chain is connected to adjacent chains by inter-molecular C-H⋯O and C-H⋯Cl inter-actions, leading to a three-dimensional network structure. The tetra-nuclear complex II lies about a crystallographic inversion centre and has one core in which two CuII metal centers are mutually inter-connected via two enolato oxygen atoms while the other two CuII cations are linked by a chloride anion and an enolato oxygen. An open-cube structure is generated in which the two open-cube units, with seven vertices each, share a side composed of two CuII ions bridged by two enolato oxygen atoms acting in a µ3-mode. The CuII atoms in each of the two CuO3NCl units are connected by one µ2-O and two µ3-O atoms from deprotonated hydroxyl groups and one chloride anion to the three other CuII centres. Each of the penta-coordinated CuII cations has a distorted NO3Cl square-pyramidal environment. The CuII atoms in each of the two CuO2NCl2 units are connected by µ2-O and µ3-O atoms from deprotonated alcohol hy-droxy groups and one chloride anion to two other CuII ions. Each of the penta-coordinated CuII cations has a distorted NO2Cl2 square-pyramidal environment. In the crystal, a series of intra-molecular C-H⋯O and C-H⋯Cl hydrogen bonds are observed in each tetra-nuclear monomeric unit, which is connected to four tetra-nuclear monomeric units by inter-molecular C-H⋯O hydrogen bonds, thus forming a planar two-dimensional structure in the (01) plane.

13.
Acta Crystallogr E Crystallogr Commun ; 74(Pt 12): 1862-1866, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30574389

RESUMO

In the penta-nuclear title complex, [SmZn2(C22H18N2O4)2(NCS)2(C3H7NO)2][Zn2(C22H18N2O4)(NCS)3]·C3H7NO·0.32H2O, namely bis-{µ2-6,6'-dimeth-oxy-2,2'-[phenyl-ene-1,2-diylbis(nitrilo-methanylyl-idene)]diphenolato}-1κ4 O,N,N',O':2κ3 O,O',O 6;2κ3 O,O',O 6:3κ4 O,N,N',O'-bis-(di-methyl-formamide-2κO)di-thiocyanato-1κN,3κN-2-samarium(III)-1,3-dizinc(II) {µ2-6,6'-dimeth-oxy-2,2'-[phenyl-ene-1,2-diylbis(nitrilo-methanylyl-idene)]diphenolato-1κ4 O,N,N',O':2κ2 O,O'}trithio-cyan-ato-1κN;2κ2 N,N-dizinc(II) di-methyl-formamide monosolvate 1.32-hydrate, a dinuclear unit and a trinuclear unit co-exist. One of the ZnII centers in the dinuclear unit as well as the two ZnII centers in the trinuclear unit are located in the inner N2O2 cavity of the ligand and are coordinated to the nitro-gen atom of one thio-cyanate moiety, giving rise to a square-pyramidal geometry. The second ZnII center in the dinuclear unit is coordinated to the two phenolate oxygen atoms of the ligand and to two thio-cyanate groups via the nitro-gen atom in a tetra-hedral geometry. The SmIII ion is eight-coordinated by four phenolate O atoms from the two ligand mol-ecules, two meth-oxy O atoms from the two ligand mol-ecules and two O atoms from the DFM solvent mol-ecule. In the dinuclear unit, the two meth-oxy oxygen atoms remain uncoordinated while in the trinuclear unit, for each ligand one meth-oxy oxygen is coordinated and the other one remains uncoordinated. In the crystal, the trinuclear cationic units and dinuclear anionic units are assembled into infinite layers. These layers are held together via electrostatic inter-actions, forming a three-dimensional structure. In the dinuclear unit, the C and S atoms of one of the thio-cyanate groups are disordered over two sets of sites in a 0.680 (4)(4):0.320 (4) ratio.

14.
Acta Crystallogr E Crystallogr Commun ; 74(Pt 6): 799-802, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29951233

RESUMO

The binuclear complex, [Sn2(C4H9)4(C16H10N4O4)], contains two Sn4+ ions, connected by doubly N-deprotonated oxalylbis[(2-oxido-benzyl-idene)hydrazide] ligands, and each Sn4+ ion is linked to two tert-butyl groups. The coordination sphere of each Sn atom is best described as a distorted trigonal bipyramid. Each stannic ion in the complex is in a C2O2N environment. The two homologous parts of the doubly deprotonated ligand are located in trans positions with respect to the C-C bond of the oxalamide group. The oxalamide group exhibits an asymmetric coordination geometry, as seen by the slight difference between the C-O and C-N bond lengths. The three-dimensional network is a multilayer of complex mol-ecules with no strong supramolecular inter-actions.

15.
Acta Crystallogr E Crystallogr Commun ; 74(Pt 4): 450-453, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29765743

RESUMO

The search for novel manganese(II) compounds having inter-esting magnetic properties, using 1-(pyridin-2-yl)-2-(pyridin-2-yl-methyl-idene)hydrazine (HL) as a tridendate ligand, led to the preparation of the title mononuclear material, [MnCl(NO3)(C11H10N4)(H2O)], and the determination of its structure by XRD. The asymmetric unit comprises a discrete mol-ecule in which the cation MnII is hepta-coordinated. The environment around the cation is an almost perfect penta-gonal bipyramid. The base is defined by the two N atoms of the pyridine rings, the N atom of the imino function of the ligand and the two O atoms of the chelating bidentate nitrate ligand. The apical positions are occupied by a Cl atom and a water mol-ecule. In the crystal, there are numerous hydrogen bonds of the types Ow-H⋯ONO2 and C-H⋯ONO2, which generate layers parallel to the bc plane in which the ligands in the axial positions point into the inter-layer space. These axial ligands give rise to hydrogen bonds of the types Ow-H⋯ONO2, Ow-H⋯Cl, N-H⋯Cl and C-H⋯Cl, leading to a three-dimensional framework. The chain bridging the two pyridine rings is disordered over two sets of sites in a 0.53 (2):0.47 (2) ratio.

16.
Acta Crystallogr E Crystallogr Commun ; 73(Pt 8): 1121-1124, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28932419

RESUMO

In the title compound, [Tb(C2H3O2)2(C11H10N4)(H2O)2]NO3·H2O, the Tb3+ ion is nine-coordinated in a distorted tricapped trigonal-prismatic geometry by the three N atoms of the tridentate 1-(pyridin-2-yl-methyl-idene)-2-(pyridin-2-yl)hydrazine ligand, four carboxyl-ate O atoms of two chelating acetate groups and two O atoms of the coordinating water mol-ecules. The organic hydrazine ligand is disordered over two orientations with a refined occupancy ratio of 0.52 (3):0.48 (3). All bond lengths in the coordination environment of the Tb3+ ion are slightly larger than those observed in the isostructural Y3+ and Er3+ complexes. In the crystal, the complex cations are linked by pairs of O-H⋯O hydrogen bonds into dimers. These dimers, nitrate anions and non-coordinating water mol-ecules are joined by O-H⋯O and N-H⋯O hydrogen bonds into a three-dimensional structure.

17.
Acta Crystallogr E Crystallogr Commun ; 73(Pt 2): 115-117, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28217323

RESUMO

The title compound, C21H36O3, contains an oxolane ring, and six defined stereocentres and may serve as a useful synthon for the synthesis of calcitriol analogues. The configurations of the chiral C atoms of the side chain were unambiguously established in the refinement. In the crystal, C-H⋯O and extremely weak O-H⋯O hydrogen bonds arising from the sterically hindered alcohol group link the mol-ecules into a three-dimensional network.

18.
Acta Crystallogr Sect E Struct Rep Online ; 70(Pt 4): o423, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24826134

RESUMO

In the title compound, C17H18N4O5·0.47CH3OH, the virtually planar (r.m.s. deviation = 0.128 Å) carbonohydrazide mol-ecule is located on a twofold axis and conformation of its C=N bonds is E. There are short intra-molecular O-H⋯N hydrogen bonds between the hy-droxy groups and hydrazide N atoms. In the crystal, bifurcated N-H⋯(O,O) hydrogen bonds assemble the carbonohydrazide mol-ecules into a three-dimensional network. There are C 2 symmetric voids in this network, 47% of which are occupied by disordered methanol mol-ecules.

19.
Acta Crystallogr Sect E Struct Rep Online ; 69(Pt 1): m24-5, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23476324

RESUMO

The title complex, [Cu(SO4)(C13H13N3)(H2O)]·4H2O, was obtained by mixing copper sulfate penta-hydrate and 2-(pyridin-2-yl)-N-(pyridin-2-yl-methyl-idene)ethanamine in eth-anol under reflux conditions. The Cu(II) ion shows a Jahn-Teller-distorted octa-hedral geometry, with equatorial positions occupied by three N atoms from the tridentate ligand (average Cu-N = 2.004 Å) and one O atom from a bidentate sulfate anion [Cu-O = 1.963 (2) Å]. The axial positions are occupied by one O atom from a coordinating water mol-ecule [Cu-O = 2.230 (3) Å] and one weakly bonded O atom [Cu-O = 2.750 (2) Å] from the bidentate sulfate ion. The complex mol-ecules are connected through O-H⋯O hydrogen bonds between the coordinating water mol-ecules and sulfate ions from neighboring complexes, forming a double chain parallel to the c axis. The chains are stabilized through additional hydrogen bonds by one of the non-coordinating water mol-ecules bridging between neighboring strands of the double chains. The remaining three water mol-ecules fill the inter-stitial space between the double chains and are involved in an intricate hydrogen-bonding network that consolidates the structure.

20.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 7): m830-1, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21836840

RESUMO

The asymmetric unit of the title complex, [Cu(C(11)H(16)N(3)O)]ClO(4), consists of two Cu(II) ions coordinated by Schiff base ligands and two perchlorate anions. The Schiff base mol-ecules are linked to the Cu(II) atoms via three N atoms and one O atom, resulting in a square-planar geometry. Inter-molecular hydrogen bonds involving the NH groups as donors and O atoms of the perchlorate anions as acceptors are observed.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA