Showing papers by "Sanjit Konar published in 2008"
TL;DR: Two novel mixed-valent manganese (Mm(II)/Mn(III)) cluster compounds were synthesized in solvothermal reactions and characterized by single-crystal X-ray diffraction, bond valence sum calculations, IR spectra, elemental analysis, and magnetic measurements.
Abstract: Two novel mixed-valent manganese (MnII/MnIII) cluster compounds were synthesized in solvothermal reactions and characterized by single-crystal X-ray diffraction, bond valence sum calculations, IR spectra, elemental analysis, and magnetic measurements. Compound 1 is a Mn19 cluster with a cylindrical core structure. Compound 2 possess a Mn16 core where all of the manganese sites have unique ligation environments. The magnetic measurements on both compounds indicate dominant antiferromagnetic interactions between the metal centers.
61 citations
TL;DR: Three new phosphonic acid ligands have been synthesized and employed in search of high molecularity iron(III) clusters and magnetic measurements reveal that there are antiferromagnetic interactions between the metal centers.
Abstract: Three new phosphonic acid ligands (4- (t)butylphenyl phosphonic acid, 3,5-dimethylphenyl phosphonic acid, and diphenylmethylphosphonic acid) have been synthesized and employed in search of high molecularity iron(III) clusters The cluster compounds are characterized by single crystal X-ray diffraction and magnetic measurements The solvothermal reaction of FeCl 36H 2O with diphenylacetic acid and p- (t)butylphenyl phosphonic acid resulted in an unprecedented dodecanuclear cluster [Fe 12(mu 2-O) 4(mu 3-O) 4(O 2CCHPh 2) 14(4- (t)buPhPO 3H) 6]( 1) having a double butterfly like core structure [Fe 12(mu 2-O) 4(mu 3-O) 4(O 2CPh) 14(C 10H 17PO 3H) 6]( 2), another dodecanuclear cluster having core structure similar to 1, has been synthesized in a reaction between [Fe 3O(O 2CPh) 6(H 2O) 3]Cl and camphylphosphonic acid in the presence of triethylamine at ambient condition 3,5-Dimethylphenyl phosphonic acid on reacting solvothermally with an oxo-centered iron triangle [Fe 3O(O 2CCMe 3) 6(H 2O) 3]Cl gives a nonanuclear cluster [Fe 9(mu 3-O) 4(O 3PPh(Me) 2) 3(O 2CCMe 3) 13]( 3) having icosahedral type core structure where three positions of the iron atoms have been replaced by phosphorus Another nonanuclear [Fe 9(O) 3(OH) 3(O 3PCHPh 2) 6(O 2CCMe 3) 6(H 2O) 9] ( 4), having a distorted cylindrical core structure, has been synthesized in a similar solvothermal reaction between [Fe 3O(O 2CCMe 3) 6(H 2O) 3]Cl and biphenylmethyl phosphonic acid All compounds are characterized by IR spectra, elemental analysis, as well as single crystal X-ray analysis Magnetic measurements for all the compounds reveal that there are antiferromagnetic interactions between the metal centers
53 citations
TL;DR: Two oxovanadium phosphonate cage compounds have been synthesized in an organic solvent, and their characterization has been done by single-crystal X-ray analysis, IR spectroscopy, and bond valence sum calculations.
Abstract: Two oxovanadium phosphonate cage compounds have been synthesized in an organic solvent, and their characterization has been done by single-crystal X-ray analysis, IR spectroscopy, and bond valence sum calculations. The simple reaction of a mixed-valent closed V12 cage system produced another quasi-closed system composed of two V6 bowl-type cages.
45 citations