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Geoffrey P. Savage - One of the best experts on this subject based on the ideXlab platform.
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Oxalate contents of raw boiled wok fried and pesto and juice made from fat hen chenopodium album leaves
2018Co-Authors: Geoffrey P. Savage, Leo P VanhanenAbstract:The total, soluble, and insoluble Oxalate contents of fresh and wok-fried fat hen (Chenopodium album) leaves were extracted and measured using High pressure liquid chromatography. The total Oxalate content of the raw leaves was 1112.4 mg/100 g dry matter (DM), and the levels were significantly reduced by boiling (682.8 mg/100 g DM) or cooking the leaves in a wok (883.6 mg/100 g DM). The percentages of soluble Oxalate contents in the total Oxalates of the raw and boiled leaves were similar (mean 75%), while the proportion of soluble Oxalate content in the wok-fried leaves was reduced to 53.4% of the total, giving a significant increase in the insoluble Oxalate content of the wok-fried leaves. The percentage of insoluble calcium in the total calcium was significantly reduced (p < 0.05) when the leaves were boiled, but the insoluble Oxalate content significantly increased (67.2%) in the wok-fried leaves when compared to the content of the original raw leaves. Processing the cooked leaves into pesto or extracting the juice gave final products that contained significantly reduced total and soluble Oxalate contents. The addition of calcium chloride to the juice caused a very small reduction in the soluble Oxalate content in the juice.
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the effects of temperature and ph on the extraction of Oxalate and pectin from green kiwifruit actinidia deliciosa l golden kiwifruit actinidia chinensis l kiwiberry actinidia arguta and persimmon diospyros kaki
International Journal of Food Science and Technology, 2013Co-Authors: Ha Vhồng Nguyễn, Geoffrey P. SavageAbstract:Summary Oxalates and pectin were extracted from four locally grown fruits at three different pH levels, 6.9, 0.6 and −0.3, at two different temperatures, 21 and 80 °C. Green kiwifruit (Actinidia deliciosa L. Hayward), golden kiwifruit (Actinidia chinensis L. Hort 16A Zespri), kiwiberry (Actinidia arguta, CV. Takaka Green) and persimmon (Diospyros kaki) contained moderate levels of Oxalates. Total and soluble Oxalates were more efficiently extracted at 21 °C using 2 m HCL, while the highest amounts of pectin were extracted from the fruits at 80 °C using 0.2 m HCL. Extraction using 0.2 and 2 m HCL gave the highest yields of total Oxalates, which ranged from 47.1 to 220.4 mg total Oxalates per 100 g dry matter (DM) for persimmon and kiwiberry, respectively. Extraction using water at 21 °C gave soluble Oxalate contents ranging from 21.2 mg 100 g−1 DM, for persimmon, to 105.0 mg 100−1 DM, for kiwiberry fruits. Extraction of pectin was not achieved efficiently using water at either temperature, while extraction using 2 m HCL gave lower values; optimal extractions of pectin were achieved at 80 °C using 0.2 m HCL.
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Oxalate contents of kiwifruit actinidia deliciosa juice extracted by pressing or enzyme extraction
2013Co-Authors: Geoffrey P. SavageAbstract:Kiwifruit juice is a popular drink made from fruit that does not meet the standard shape and size required for direct consumption of the fruit. Extraction of the juice and pasteurisation may have an effect on the Oxalate concentration of the processed juice. Total and soluble Oxalate contents of extracted and processed juice were determined by HPLC chromatography. The levels were determined in the juice and pomace of pressed and enzyme-treated fruit and in the juice following pasteurisation. Oxalate contents of peeled green kiwifruit (Actinidia deliciosa var. Hayward) were 21.2 ± 0.33, 6.9 ± 0.03, 14.3 ± 0.05 (mg/100 g fresh weight) for total, soluble and insoluble Oxalates, respectively. Treatment of the homogenised kiwifruit at 21°C for four hours with pectolase increased (p < 0.01) the yield of extracted juice. Higher levels of total and soluble Oxalates (p < 0.01) were found in green kiwifruit juice obtained by enzymatic extraction compared with juice obtained by pressing. Most of the insoluble Oxalate from the fresh kiwifruit was retained in the pomace during juice extraction. Soluble Oxalate made up 59.3% of the total Oxalate in the juice extracted by pressing while it constituted 66.8% of the juice extracted by enzyme extraction, compared with 32.7% in the fresh pealed tissue. Pasteurisation at 90°C significantly (p < 0.01) reduced the soluble Oxalate content of both the pressed and enzyme treated kiwifruit juice but had no effect on the total Oxalate content of the two juices.
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comparison of the estimates of the Oxalate content of taro leaves and corms and a selection of indian vegetables following hot water hot acid and in vitro extraction methods
Journal of Food Composition and Analysis, 2010Co-Authors: Geoffrey P. Savage, L MartenssonAbstract:Total, soluble, gastric soluble and intestinal soluble Oxalates were determined using three groups of foods. The total and soluble Oxalate contents were extracted using hot acid (80 °C, 0.2 mol/l HCl) and hot water (80 °C). Gastric soluble and intestinal soluble Oxalates were extracted using an in vitro method; the food samples were incubated for 2 h at 37 °C in gastric and intestinal juice. The extracted Oxalates obtained from both methods were then determined by HPLC chromatography. The Oxalate contents of taro leaves were determined in the raw leaves and after being baked at 150 °C for 1.5 h either alone or with additions of cows’ milk or coconut milk prior to baking. The Oxalate contents of four different cultivars of taro corms were determined in the raw corms and after the corms had been either boiled or baked. The Oxalate contents of a selection of green leafy Indian vegetables were also determined in the dried raw material. Overall, the total Oxalate contents of the foods analysed in this study ranged from 209 mg Oxalate/100 g dry matter (DM) for raw Indian radish leaves to 12,576 mg Oxalate/100 g DM for raw Indian spinach leaves, while the soluble Oxalate contents of the samples ranged from 143 mg soluble Oxalate for raw taro corms to 11,900 mg soluble Oxalate/100 g DM for raw Indian spinach leaves. Regression analysis of all the gastric soluble Oxalate values against the total Oxalate values showed that there was a good fit (R2 = 0.955). However, the gastric soluble Oxalate values were, on average, 14.2 ± 3.7% lower than those for total Oxalate obtained by hot acid extraction. Regression analysis of all the intestinal soluble Oxalate contents against the soluble Oxalate values showed a good fit between the values (R2 = 0.967). Overall, the intestinal soluble Oxalate values were 10.0 ± 6.6% lower than those for soluble Oxalate obtained by hot water extraction.
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composition of Oxalates in baked taro colocasia esculenta var schott leaves cooked alone or with additions of cows milk or coconut milk
Journal of Food Composition and Analysis, 2009Co-Authors: Geoffrey P. Savage, L Martensson, J R SedcoleAbstract:Abstract Taro ( Colocasia esculenta var. Schott) is a major staple food crop in parts of Asia and the Pacific Islands and two different cultivars of taro plants Taro Tonga ( C. esculenta ) and Taro Futuna ( Xanthosoma sagittifolium ), known respectively as Maori and Japanese, are grown as a minor crop in New Zealand. The leaves are either boiled or baked before they are consumed. In this experiment the leaves were baked at 150 °C for 1.5 h either alone or with additions of cows milk and coconut milk prior to baking. Oxalate contents of both cultivars of leaves were determined following extraction by either hot distilled water (80 °C) to give soluble Oxalates or hot (80 °C) acid (0.2 mol/l HCl) to give total Oxalates. The extracted Oxalates were then determined by HPLC chromatography. Baked Maori-type taro leaves contained 719.3 ± 12.0 mg total Oxalates/100 g fresh weight (FW) and 365.9 ± 11.4 soluble Oxalates/100 g FW while baked Japanese-type leaves contained 533.9 ± 14.9 mg total Oxalates/100 g FW and 352.6 ± 8.4 mg soluble Oxalates/100 g FW. The total and soluble Oxalate content of the baked leaves was considerably reduced when the leaves were baked with cows milk, coconut milk or mixtures of these two (mean % reduction of total Oxalates was 43.2 ± 3.8% while the mean % reduction of soluble Oxalates was 58.7 ± 1.8%).
Miguel Julve - One of the best experts on this subject based on the ideXlab platform.
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A Two-Dimensional Oxamate- and Oxalate-Bridged CuIIMnII Motif: Crystal Structure and Magnetic Properties of (Bu4N)2[Mn2{Cu(opba)}2ox]
2016Co-Authors: Maria V. Marinho, Marcos A Ribeiro, Flavia C Machado, Carlos B Pinheiro, Humberto O Stumpf, Joan Cano, Francesc Lloret, Tatiana R. G. Simões, Cynthia L. M. Pereira, Miguel JulveAbstract:A new compound of formula (Bu4N)2[Mn2{Cu(opba)}2ox] (1) [Bu4N+ = tetra-n-butylammonium cation, H4opba = 1,2-phenylenebis(oxamic acid), and H2ox = oxalic acid] has been synthesized and magneto-structurally investigated. The reaction of manganese(II) acetate, [Cu(opba)]2–, and ox2– in dimethyl sulfoxide yielded single crystals of 1. The structure of 1 consists of heterobimetallic oxamato-bridged CuIIMnII chains which are connected through bis-bidentate Oxalate coordinated to the manganese(II) ions to afford anionic heterobimetallic layers of 63-hcb net topology. The layers are interleaved by n-Bu4N+ counterions. Each copper(II) ion in 1 is four-coordinate in a square planar environment defined by two amidate-nitrogen and two carboxylate-oxygen atoms from the two oxamate groups of the obpa ligand. The manganese(II) ion is six-coordinate in a somewhat distorted octahedral surrounding that is built by two Oxalate-oxygen and four carbonyl-oxygen atoms from two [Cu(opba)]2– units. The magnetic properties of 1 in the temperature range 1.9–300 K correspond to those expected for the coexistence of intralayer antiferromagnetic interactions of the type copper(II)–manganese(II) across oxamato and manganese(II)–manganese(II) through oxalato bridges plus a weak spin canting in the very low temperature domain. Simulation of the magnetic data through quantum Monte Carlo methodology reveals the magnitude of the intralayer magnetic interactions [JCuMn = −32.5(3) cm–1, and JMnMn = −2.7(3) cm–1], their values being within the range of those previously observed in lower nuclearity systems
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a two dimensional oxamate and Oxalate bridged cu ii mn ii motif crystal structure and magnetic properties of bu4n 2 mn2 cu opba 2ox
Inorganic Chemistry, 2013Co-Authors: Maria Vanda Marinho, Tatiana R G Simoes, Marcos A Ribeiro, Cynthia L M Pereira, Flavia C Machado, Carlos B Pinheiro, Humberto O Stumpf, Joan Cano, Francesc Lloret, Miguel JulveAbstract:A new compound of formula (Bu4N)2[Mn2{Cu(opba)}2ox] (1) [Bu4N(+) = tetra-n-butylammonium cation, H4opba = 1,2-phenylenebis(oxamic acid), and H2ox = oxalic acid] has been synthesized and magneto-structurally investigated. The reaction of manganese(II) acetate, [Cu(opba)](2-), and ox(2-) in dimethyl sulfoxide yielded single crystals of 1. The structure of 1 consists of heterobimetallic oxamato-bridged Cu(II)Mn(II) chains which are connected through bis-bidentate Oxalate coordinated to the manganese(II) ions to afford anionic heterobimetallic layers of 6(3)-hcb net topology. The layers are interleaved by n-Bu4N(+) counterions. Each copper(II) ion in 1 is four-coordinate in a square planar environment defined by two amidate-nitrogen and two carboxylate-oxygen atoms from the two oxamate groups of the obpa ligand. The manganese(II) ion is six-coordinate in a somewhat distorted octahedral surrounding that is built by two Oxalate-oxygen and four carbonyl-oxygen atoms from two [Cu(opba)](2-) units. The magnetic properties of 1 in the temperature range 1.9-300 K correspond to those expected for the coexistence of intralayer antiferromagnetic interactions of the type copper(II)-manganese(II) across oxamato and manganese(II)-manganese(II) through oxalato bridges plus a weak spin canting in the very low temperature domain. Simulation of the magnetic data through quantum Monte Carlo methodology reveals the magnitude of the intralayer magnetic interactions [J(CuMn) = -32.5(3) cm(-1), and J(MnMn) = -2.7(3) cm(-1)], their values being within the range of those previously observed in lower nuclearity systems.
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one dimensional oxalato bridged copper ii complexes with 3 hydroxypyridine and 2 amino 4 methylpyridine
Inorganica Chimica Acta, 2001Co-Authors: Oscar Castillo, Miguel Julve, Francesc Lloret, Antonio Luque, Pascual RomanAbstract:Two new one-dimensional oxalato-bridged copper(II) compounds of formula [Cu(ox)L2]n (1) and {[Cu2(ox)2L%3]·L%}n (2) [ox Oxalate dianion, L3-hydroxypyridine (pyOH) and L% 2-amino-4-methylpyridine (ampy)] have been synthesized and characterized by FT-IR spectroscopy, variable-temperature magnetic measurements and single-crystal X-ray diffraction. The crystal structure of 1 comprises chains of copper atoms in which cis-[Cu(pyOH)2] 2 units are sequentially bridged by asymmetric bis-bidentate oxalato ligands with an intrachain copper‐copper separation of 5.548(1) A, . Each copper atom is six-coordinated: four oxygen atoms belonging to two bridging oxalato ligands and two nitrogen atoms from two 3-hydroxypyridine ligands build a distorted octahedral environment around the metal atom. As in 1, the structure of compound 2 is made up of chains of copper atoms bridged sequentially by bis-bidentate oxalato ligands. Two types of copper(II) ion, one being six-coordinated (Cu(1)) and the other five-coordinated (Cu(2)), alternate regularly within the chain. The environment around Cu(1) is elongated octahedral with two cis-coordinated pyridine‐nitrogen and two oxygen atoms from two Oxalate ligands building the equatorial plane, the apical positions being filled by two Oxalate-oxygen atoms. The environment around Cu(2) is distorted square pyramidal with four oxalato-oxygen atoms in the basal plane, and the pyridine nitrogen atom from one aromatic base in the apical position. Magnetic susceptibility data in the temperature range 2.0‐300 K reveal regular ferromagnetic (J 1.3 cm 1 ) and alternating antiferromagnetic (J66.6 cm 1 , aJ58.6 cm 1 ) chain behaviours for 1 and 2. The nature and magnitude of the magnetic coupling through the oxalato bridge in 1 and 2 are analysed and discussed in the light of the available structural data. © 2001 Elsevier Science B.V. All rights reserved.
J R Sedcole - One of the best experts on this subject based on the ideXlab platform.
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composition of Oxalates in baked taro colocasia esculenta var schott leaves cooked alone or with additions of cows milk or coconut milk
Journal of Food Composition and Analysis, 2009Co-Authors: Geoffrey P. Savage, L Martensson, J R SedcoleAbstract:Abstract Taro ( Colocasia esculenta var. Schott) is a major staple food crop in parts of Asia and the Pacific Islands and two different cultivars of taro plants Taro Tonga ( C. esculenta ) and Taro Futuna ( Xanthosoma sagittifolium ), known respectively as Maori and Japanese, are grown as a minor crop in New Zealand. The leaves are either boiled or baked before they are consumed. In this experiment the leaves were baked at 150 °C for 1.5 h either alone or with additions of cows milk and coconut milk prior to baking. Oxalate contents of both cultivars of leaves were determined following extraction by either hot distilled water (80 °C) to give soluble Oxalates or hot (80 °C) acid (0.2 mol/l HCl) to give total Oxalates. The extracted Oxalates were then determined by HPLC chromatography. Baked Maori-type taro leaves contained 719.3 ± 12.0 mg total Oxalates/100 g fresh weight (FW) and 365.9 ± 11.4 soluble Oxalates/100 g FW while baked Japanese-type leaves contained 533.9 ± 14.9 mg total Oxalates/100 g FW and 352.6 ± 8.4 mg soluble Oxalates/100 g FW. The total and soluble Oxalate content of the baked leaves was considerably reduced when the leaves were baked with cows milk, coconut milk or mixtures of these two (mean % reduction of total Oxalates was 43.2 ± 3.8% while the mean % reduction of soluble Oxalates was 58.7 ± 1.8%).
L Martensson - One of the best experts on this subject based on the ideXlab platform.
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comparison of the estimates of the Oxalate content of taro leaves and corms and a selection of indian vegetables following hot water hot acid and in vitro extraction methods
Journal of Food Composition and Analysis, 2010Co-Authors: Geoffrey P. Savage, L MartenssonAbstract:Total, soluble, gastric soluble and intestinal soluble Oxalates were determined using three groups of foods. The total and soluble Oxalate contents were extracted using hot acid (80 °C, 0.2 mol/l HCl) and hot water (80 °C). Gastric soluble and intestinal soluble Oxalates were extracted using an in vitro method; the food samples were incubated for 2 h at 37 °C in gastric and intestinal juice. The extracted Oxalates obtained from both methods were then determined by HPLC chromatography. The Oxalate contents of taro leaves were determined in the raw leaves and after being baked at 150 °C for 1.5 h either alone or with additions of cows’ milk or coconut milk prior to baking. The Oxalate contents of four different cultivars of taro corms were determined in the raw corms and after the corms had been either boiled or baked. The Oxalate contents of a selection of green leafy Indian vegetables were also determined in the dried raw material. Overall, the total Oxalate contents of the foods analysed in this study ranged from 209 mg Oxalate/100 g dry matter (DM) for raw Indian radish leaves to 12,576 mg Oxalate/100 g DM for raw Indian spinach leaves, while the soluble Oxalate contents of the samples ranged from 143 mg soluble Oxalate for raw taro corms to 11,900 mg soluble Oxalate/100 g DM for raw Indian spinach leaves. Regression analysis of all the gastric soluble Oxalate values against the total Oxalate values showed that there was a good fit (R2 = 0.955). However, the gastric soluble Oxalate values were, on average, 14.2 ± 3.7% lower than those for total Oxalate obtained by hot acid extraction. Regression analysis of all the intestinal soluble Oxalate contents against the soluble Oxalate values showed a good fit between the values (R2 = 0.967). Overall, the intestinal soluble Oxalate values were 10.0 ± 6.6% lower than those for soluble Oxalate obtained by hot water extraction.
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composition of Oxalates in baked taro colocasia esculenta var schott leaves cooked alone or with additions of cows milk or coconut milk
Journal of Food Composition and Analysis, 2009Co-Authors: Geoffrey P. Savage, L Martensson, J R SedcoleAbstract:Abstract Taro ( Colocasia esculenta var. Schott) is a major staple food crop in parts of Asia and the Pacific Islands and two different cultivars of taro plants Taro Tonga ( C. esculenta ) and Taro Futuna ( Xanthosoma sagittifolium ), known respectively as Maori and Japanese, are grown as a minor crop in New Zealand. The leaves are either boiled or baked before they are consumed. In this experiment the leaves were baked at 150 °C for 1.5 h either alone or with additions of cows milk and coconut milk prior to baking. Oxalate contents of both cultivars of leaves were determined following extraction by either hot distilled water (80 °C) to give soluble Oxalates or hot (80 °C) acid (0.2 mol/l HCl) to give total Oxalates. The extracted Oxalates were then determined by HPLC chromatography. Baked Maori-type taro leaves contained 719.3 ± 12.0 mg total Oxalates/100 g fresh weight (FW) and 365.9 ± 11.4 soluble Oxalates/100 g FW while baked Japanese-type leaves contained 533.9 ± 14.9 mg total Oxalates/100 g FW and 352.6 ± 8.4 mg soluble Oxalates/100 g FW. The total and soluble Oxalate content of the baked leaves was considerably reduced when the leaves were baked with cows milk, coconut milk or mixtures of these two (mean % reduction of total Oxalates was 43.2 ± 3.8% while the mean % reduction of soluble Oxalates was 58.7 ± 1.8%).
Francesc Lloret - One of the best experts on this subject based on the ideXlab platform.
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A Two-Dimensional Oxamate- and Oxalate-Bridged CuIIMnII Motif: Crystal Structure and Magnetic Properties of (Bu4N)2[Mn2{Cu(opba)}2ox]
2016Co-Authors: Maria V. Marinho, Marcos A Ribeiro, Flavia C Machado, Carlos B Pinheiro, Humberto O Stumpf, Joan Cano, Francesc Lloret, Tatiana R. G. Simões, Cynthia L. M. Pereira, Miguel JulveAbstract:A new compound of formula (Bu4N)2[Mn2{Cu(opba)}2ox] (1) [Bu4N+ = tetra-n-butylammonium cation, H4opba = 1,2-phenylenebis(oxamic acid), and H2ox = oxalic acid] has been synthesized and magneto-structurally investigated. The reaction of manganese(II) acetate, [Cu(opba)]2–, and ox2– in dimethyl sulfoxide yielded single crystals of 1. The structure of 1 consists of heterobimetallic oxamato-bridged CuIIMnII chains which are connected through bis-bidentate Oxalate coordinated to the manganese(II) ions to afford anionic heterobimetallic layers of 63-hcb net topology. The layers are interleaved by n-Bu4N+ counterions. Each copper(II) ion in 1 is four-coordinate in a square planar environment defined by two amidate-nitrogen and two carboxylate-oxygen atoms from the two oxamate groups of the obpa ligand. The manganese(II) ion is six-coordinate in a somewhat distorted octahedral surrounding that is built by two Oxalate-oxygen and four carbonyl-oxygen atoms from two [Cu(opba)]2– units. The magnetic properties of 1 in the temperature range 1.9–300 K correspond to those expected for the coexistence of intralayer antiferromagnetic interactions of the type copper(II)–manganese(II) across oxamato and manganese(II)–manganese(II) through oxalato bridges plus a weak spin canting in the very low temperature domain. Simulation of the magnetic data through quantum Monte Carlo methodology reveals the magnitude of the intralayer magnetic interactions [JCuMn = −32.5(3) cm–1, and JMnMn = −2.7(3) cm–1], their values being within the range of those previously observed in lower nuclearity systems
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a two dimensional oxamate and Oxalate bridged cu ii mn ii motif crystal structure and magnetic properties of bu4n 2 mn2 cu opba 2ox
Inorganic Chemistry, 2013Co-Authors: Maria Vanda Marinho, Tatiana R G Simoes, Marcos A Ribeiro, Cynthia L M Pereira, Flavia C Machado, Carlos B Pinheiro, Humberto O Stumpf, Joan Cano, Francesc Lloret, Miguel JulveAbstract:A new compound of formula (Bu4N)2[Mn2{Cu(opba)}2ox] (1) [Bu4N(+) = tetra-n-butylammonium cation, H4opba = 1,2-phenylenebis(oxamic acid), and H2ox = oxalic acid] has been synthesized and magneto-structurally investigated. The reaction of manganese(II) acetate, [Cu(opba)](2-), and ox(2-) in dimethyl sulfoxide yielded single crystals of 1. The structure of 1 consists of heterobimetallic oxamato-bridged Cu(II)Mn(II) chains which are connected through bis-bidentate Oxalate coordinated to the manganese(II) ions to afford anionic heterobimetallic layers of 6(3)-hcb net topology. The layers are interleaved by n-Bu4N(+) counterions. Each copper(II) ion in 1 is four-coordinate in a square planar environment defined by two amidate-nitrogen and two carboxylate-oxygen atoms from the two oxamate groups of the obpa ligand. The manganese(II) ion is six-coordinate in a somewhat distorted octahedral surrounding that is built by two Oxalate-oxygen and four carbonyl-oxygen atoms from two [Cu(opba)](2-) units. The magnetic properties of 1 in the temperature range 1.9-300 K correspond to those expected for the coexistence of intralayer antiferromagnetic interactions of the type copper(II)-manganese(II) across oxamato and manganese(II)-manganese(II) through oxalato bridges plus a weak spin canting in the very low temperature domain. Simulation of the magnetic data through quantum Monte Carlo methodology reveals the magnitude of the intralayer magnetic interactions [J(CuMn) = -32.5(3) cm(-1), and J(MnMn) = -2.7(3) cm(-1)], their values being within the range of those previously observed in lower nuclearity systems.
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one dimensional oxalato bridged copper ii complexes with 3 hydroxypyridine and 2 amino 4 methylpyridine
Inorganica Chimica Acta, 2001Co-Authors: Oscar Castillo, Miguel Julve, Francesc Lloret, Antonio Luque, Pascual RomanAbstract:Two new one-dimensional oxalato-bridged copper(II) compounds of formula [Cu(ox)L2]n (1) and {[Cu2(ox)2L%3]·L%}n (2) [ox Oxalate dianion, L3-hydroxypyridine (pyOH) and L% 2-amino-4-methylpyridine (ampy)] have been synthesized and characterized by FT-IR spectroscopy, variable-temperature magnetic measurements and single-crystal X-ray diffraction. The crystal structure of 1 comprises chains of copper atoms in which cis-[Cu(pyOH)2] 2 units are sequentially bridged by asymmetric bis-bidentate oxalato ligands with an intrachain copper‐copper separation of 5.548(1) A, . Each copper atom is six-coordinated: four oxygen atoms belonging to two bridging oxalato ligands and two nitrogen atoms from two 3-hydroxypyridine ligands build a distorted octahedral environment around the metal atom. As in 1, the structure of compound 2 is made up of chains of copper atoms bridged sequentially by bis-bidentate oxalato ligands. Two types of copper(II) ion, one being six-coordinated (Cu(1)) and the other five-coordinated (Cu(2)), alternate regularly within the chain. The environment around Cu(1) is elongated octahedral with two cis-coordinated pyridine‐nitrogen and two oxygen atoms from two Oxalate ligands building the equatorial plane, the apical positions being filled by two Oxalate-oxygen atoms. The environment around Cu(2) is distorted square pyramidal with four oxalato-oxygen atoms in the basal plane, and the pyridine nitrogen atom from one aromatic base in the apical position. Magnetic susceptibility data in the temperature range 2.0‐300 K reveal regular ferromagnetic (J 1.3 cm 1 ) and alternating antiferromagnetic (J66.6 cm 1 , aJ58.6 cm 1 ) chain behaviours for 1 and 2. The nature and magnitude of the magnetic coupling through the oxalato bridge in 1 and 2 are analysed and discussed in the light of the available structural data. © 2001 Elsevier Science B.V. All rights reserved.
