Structural and Electronic Properties of Iron(II) Complexes of 2-(1,2,4-Triazol-3-yl)pyridine and Substituted Derivatives

1995 ◽  
Vol 48 (1) ◽  
pp. 35 ◽  
Author(s):  
KH Sugiyarto ◽  
DC Craig ◽  
AD Rae ◽  
HA Goodwin
Keyword(s):  
Metal Ion ◽  
Complex Cation ◽  
Iron Complex ◽  
High Symmetry ◽  
Orthorhombic Space Group ◽  
Metastable Form ◽  
Structural And Electronic Properties ◽  
Region Temperature ◽  
A Minor

Iron(II) and nickel(II) tris(ligand) complexes of 2-(triazol-3-yl)pyridine and the substituted derivatives 2-(1(N)-methyltriazol-3-yl)pyridine and -(1,5-dimethyltriazol-3-yl)pyridine have been prepared. Coordination of the dimethyl -substituted ligand via N(4) of the triazolyl moieties is confirmed by structure determination of [FeL3] [BF4]2, which has the mer configuration. Tris (2-(1,5-dimethyltriazol-3-yl)pyridine)iron(II) bis ( tetrafluoroborate ): orthorhombic, space group Pbca, a 11.568(3), b 19.442(4), c 30.551(8) Ǻ, Z 8. The methyl substituents appear to have only a minor influence on the donor properties of the ligands, all three of which have field strengths in the iron(II) quintet ↔ singlet crossover region. Temperature-induced singlet ↔ quintet transitions occur in salts of the [FeN6]2+ derivatives in both the solid and solution states. Mossbauer effect studies reveal the complexity of the solid state properties of salts of the iron complex of 2-(1(N)-methyltriazol-3-yl)pyridine and suggest that there is a fundamental change with time in the geometry of the complex cation. The metastable form of the complex hexafluorophosphate salt shows virtually no quadrupole splitting in the spectrum for the quintet state species, which implies high symmetry for the metal ion environment. Mossbauer studies further reveal the presence of multiple iron(II) sites in the lattice for salts containing either the N-methyl or the unsubstituted ligand.

Structural Characterization of Encapsulation Reactions Based on the Tris(ethane-1,2-diamine)cobalt(III) Ion

1993 ◽  
Vol 46 (10) ◽  
pp. 1485 ◽  
Author(s):  
IJ Clark ◽  
RJ Geue ◽  
LM Engelhardt ◽  
JM Harrowfield ◽  
AM Sargeson ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Metal Ion ◽  
Bond Angle ◽  
Orthorhombic Space Group ◽  
Molecular Rearrangement ◽  
Coordination Environment ◽  
Catalysed Reaction ◽  
Structural And Electronic Properties ◽  
Coordination Spheres

On the basis of structural comparisons involving intermediates and side products of encapsulation reactions as well as several cage complexes, the efficiency of the base- catalysed reaction between formaldehyde, nitromethane and [Co(en)3]3+ (en = ethane-1,2-diamine) to give [Co((NO2)2sar)]3+ appears to be explicable in terms of the 'interlocking' of constituent parts without appreciable concomitant bond length or bond angle distortions. Thus, the structures of the podand ligand complexes Λ-[Co(NO2sen)]Cl3.2H2O [orthorhombic, space group P 212121, a 18.755(6), b 11.598(4), c 9.164(3) Ǻ; R 0.038 for No 1735 'observed' reflections] and Δ,Λ-[Co(Nt-Me,NO2sen)]Cl3.4H2O [monoclinic, P21/n, a 18.613(5), b 9.301(3), c 13.779(4) Ǻ, β 107.10(2)°; R 0.051 for No 26441 show very close configurational and conformational similarities to those of the cage complexes Δ,Λ-[Co(NO2azasar)]Cl3.3H2O [monoclinic, P 21/c, a 9.339(3), b 15.479(9), c 17.360(7)Ǻ, β 114.15(3)°; R 0.048 for No 2612], Δ,Λ-[Co((NO2)2sar)]Cl3.2H2O [triclinic, Pī , a 13.592(3), b 10.024(3), c 9.772(3)Ǻ, α 62.89(2),β 82.96(3), γ 85.15(2)°; R 0.045 for No 5646] and Δ,Λ-[Co((OH)2sar)]Cl3.3H2O [monoclinic, P21/c, a 15.97(1), b 8.758(4), c 16.760(4)Ǻ, β 98.72(4)°; R 0.052 for No 2400], as well as to published structures of [Co(en)3]3+, [Co(tame)2]3+ [tame = 1,1,1-tris- ( aminomethyl )ethane = ethylidynetris ( methanamine )] and other cage complexes. Some of these similarities may be associated with common hydrogen-bonding patterns in the solids resulting from anion ' chelation' by adjacent NH moieties in the metal ion coordination spheres. Necessary caution in relating structural and electronic properties is implied by the structure determination for Δ,Λ [Co(Cl,ClCH2absar)](NO3)3 [monoclinic, P 21/c, a 14.750(6), b 9.264(3), c 17.959(7) Ǻ, β 95.80(3)°; R 0.061 for No 1431], one of the products of molecular rearrangement following nitrosation of [Co((NH2)2sar)]3+. Despite marked electronic spectral and electrochemical differences with its parent complex, [Co(Cl,ClCH2absar)](NO3)3 contains cobalt(III) in a coordination environment which remains similar to those in more symmetrical cage complexes.

Protonation effects on dynamic flux properties of aqueous metal complexes

2009 ◽  
Vol 74 (10) ◽  
pp. 1543-1557 ◽  
Author(s):  
Herman P. Van Leeuwen ◽  
Raewyn M. Town
Keyword(s):  
Complex Formation ◽  
Metal Ion ◽  
Good Description ◽  
Minor Component ◽  
Outer Sphere ◽  
Metal Species ◽  
Central Metal ◽  
Inner Sphere ◽  
A Minor ◽  
Protonated Ligand

The degree of (de)protonation of aqueous metal species has significant consequences for the kinetics of complex formation/dissociation. All protonated forms of both the ligand and the hydrated central metal ion contribute to the rate of complex formation to an extent weighted by the pertaining outer-sphere stabilities. Likewise, the lifetime of the uncomplexed metal is determined by all the various protonated ligand species. Therefore, the interfacial reaction layer thickness, μ, and the ensuing kinetic flux, Jkin, are more involved than in the conventional case. All inner-sphere complexes contribute to the overall rate of dissociation, as weighted by their respective rate constants for dissociation, kd. The presence of inner-sphere deprotonated H2O, or of outer-sphere protonated ligand, generally has a great impact on kd of the inner-sphere complex. Consequently, the overall flux can be dominated by a species that is a minor component of the bulk speciation. The concepts are shown to provide a good description of experimental stripping chronopotentiometric data for several protonated metal–ligand systems.

Two lithium tricyanomethanide compounds: syntheses and single-crystal structure determination of LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO

2015 ◽  
Vol 70 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Structure Determination ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Cell Parameters ◽  
New Compounds

AbstractThe new compounds LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO were synthesized and their crystal structures were determined. Li[C(CN)3]·½ (H3C)2CO crystallizes in the orthorhombic space group Ima2 (no. 46) with the cell parameters a=794.97(14), b=1165.1(2) and c=1485.4(3) pm, while LiK[C(CN)3]2 adopts the monoclinic space group P21/c (no. 14) with the cell parameters a=1265.7(2), b=1068.0(2) and c=778.36(12) pm and the angle β=95.775(7)°. Single crystals of K[C(CN)3] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.

Green synthesis of gold nanoparticles and its application for the trace level determination of painter's colic

RSC Advances ◽  
2015 ◽  
Vol 5 (21) ◽  
pp. 16284-16291 ◽  
Author(s):  
Chelladurai Karuppiah ◽  
Selvakumar Palanisamy ◽  
Shen-Ming Chen ◽  
R. Emmanuel ◽  
K. Muthupandi ◽  
...  
Keyword(s):  
Analytical Chemistry ◽  
Heavy Metal ◽  
Green Synthesis ◽  
Metal Ion ◽  
Trace Level ◽  
Ion Sensing ◽  
Metal Ion Sensing ◽  
Heavy Metal Ion Sensing ◽  
Trace Level Determination

The green synthesis of metal nanoparticles is found to be more attractive in various disciplines, including in analytical chemistry for heavy metal ion sensing.

Features of the course of birth in northern domestic deer in the conditions of the North-East of Russia (Yakutia)

2021 ◽  
pp. 23-28
Author(s):  
V. Fedorov ◽  
T. Ippolitova ◽  
E. Sleptsov ◽  
K. Plemyashov
Keyword(s):  
Living Environment ◽  
Behavioral Reactions ◽  
Climatic Zones ◽  
North East ◽  
The North ◽  
The Republic ◽  
A Minor ◽  
Harsh Conditions ◽  
Generic Process

Purpose: Determination of the peculiarities of the behavior and the flow of childbirth in females (wrenches) of the northern home deer of the Even Breed of the Republic of Sakha (Yakutia), depending on the natural climatic zone of breeding.Material and research methods. Research of the reservation of the hotel's reservoir of the northern home deer was held from April to June in the reindeer herds of the mountain-taiga (FSUE «Yuchjuyuskoye») and the Tundrov zones (SHPZK «Taba-Yana») of the Republic of Sakha (Yakutia) in the conditions of nomadic home reindeer herding since 2013 2018 In the study, the method of observation is used with the registration of motor activity of animals and the activities of individual bodies in a certain living environment.Results. To fix some patterns and species features of the generic process, 8 main elementary behavioral reactions spent venizables of northern domestic deer per day before childbirth: walking, feeding feed, chewing, leisure standing, rest lying, sleep, urination (how many times / total time), defecation (how many times / total time). Also marked 4 behavioral reactions on the hotel day: the exploitation time of the fetus, the licking of the calf, the time of the calf on his feet after delivery, the first reception of the mosper calf after birth. For each parameter, data reflected in tabular format is obtained.Conclusion. It has been established that the degree of adaptation of the northern domestic deer to the harsh conditions of existence in various natural-climatic zones of the Republic of Sakha (Yakutia) is very high, which is manifested in a minor difference in the duration of the generic process and behavioral reactions at the vainer of the mountain and tundra and tundra dilution zones.

Metal complex pigments

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert Christie ◽  
Adrian Abel
Keyword(s):  
Metal Complex ◽  
Metal Ion ◽  
Copper Phthalocyanine ◽  
Research Effort ◽  
Iron Complex ◽  
Organic Pigment ◽  
Organic Pigments ◽  
Printing Inks ◽  
Green Pigments ◽  
Complex Organic

Abstract There are several commercially significant metal complex organic pigments that are based on first row transition metals. The most important of these are the copper phthalocyanine blue and green pigments which find virtually universal use in paints, printing inks, and plastics. These pigments are of such prime importance that they are dealt with separately in three other chapters in this series. This paper describes a group of pigments that are complexes of iron, copper, nickel, and cobalt with polydentate colored ligands of azo, azomethine, oxime, and isoindoline chemical types. The oldest metal complex organic pigment that still finds some use is CI Pigment Green 8, an octahedral oxime iron complex. In the 1970s and 1980s, there was considerable industrial research effort aimed at developing metal complex pigments based on azomethine and isoindoline structures, many of which were found to offer excellent lightfastness, good solvent resistance and thermal stability, although they exhibited rather dull colors. However, several products provide brilliant effects when used in combination with metallic and pearlescent pigments in automotive paints. Many of the pigments introduced have since been withdrawn by the original manufacturers, but a few remain on the market. The synthesis of metal complex pigments generally involves the preparation of the colored ligand, which is then complexed with the transition metal ion

Structural and Electronic Properties of the Iron(II) and Nickel(II) Bis(ligand) Complexes of 6-(5-Methyl-1,2,4-oxadiazol-3-yl)-2,2′-bipyridine— a Terpyridine-Based Tridentate

1999 ◽  
Vol 52 (7) ◽  
pp. 673 ◽  
Author(s):  
Bradley J. Childs ◽  
Marcia L. Scudder ◽  
Donald C. Craig ◽  
Harold A. Goodwin
Keyword(s):  
Electronic Properties ◽  
Spectroscopic Data ◽  
Room Temperature ◽  
Spin Transition ◽  
Iron Complex ◽  
Ligand Field ◽  
Monoclinic Space Group ◽  
Space Group ◽  
C 23 ◽  
Structural And Electronic Properties

Iron(II) and nickel(II) bis(ligand) complexes of 6-(5-methyl-1,2,4-oxadiazol-3-yl)-2,2′-bipyridine (L) are described. The ligand field in the iron complex is close to that at the singlet ( 1 A1) ? quintet ( 5 T2) crossover and magnetic and Mössbauer spectral evidence indicates that a spin transition occurs in salts of the iron complex but is centred above room temperature. The structures of [FeL2] [CF3SO3]2.CH3CN and [NiL2] [BF4]2.CH3CN were determined and both are very similar to the structures of the corresponding terpyridine complexes. Spectroscopic data indicate that for the iron complex π-interaction between the metal and the ligand is less than that in the terpyridine system. [FeL2] [CF3SO3]2.CH3CN is monoclinic, space group P 21/c; a 8 . 232(5), b 25 . 273(10), c 17 . 306(10) Å, β 92 . 37(3)°, Z 4; [NiL2] [BF4]2.CH3CN is monoclinic, space group P 21/c; a 8 . 136(2), b 17 . 558(2), c 23 . 783(7) Å, β 109 . 32(1)°, Z 4.

Determination of Solution Ions by Electrospray Mass Spectrometry

1994 ◽  
Vol 48 (6) ◽  
pp. 655-661 ◽  
Author(s):  
George R. Agnes ◽  
Gary Horlick
Keyword(s):  
Mass Spectrometry ◽  
Metal Ion ◽  
Gas Flow ◽  
Electrospray Mass Spectrometry ◽  
Negative Ion ◽  
Molecular Forms ◽  
Mass Spectral ◽  
Oxo Anions ◽  
Electrospray Source

Spectral results are presented illustrating the capability of electrospray mass spectrometry (ES-MS) for the determination of the composition of solution samples. The solution components that can be determined include the elemental and molecular forms of anions and cations. Three modes of positive-ion ES-MS are described: the ion cluster mode, the metal-ion mode, and an intermediate mode. The modes are established by operating the electrospray source at specific voltages and curtain gas flow rate values, and each mode provides a unique mass spectral picture of the solution components with primary focus on cationic species (i.e., metal ions). Results are also presented for operation of the electrospray source in negative-ion mode. In this mode both elemental anions (i.e., halides) and molecular anions (i.e., oxo-anions) can be determined.

Isolation of radioactive iodothyronines for kinetic studies: a comparison of two methods

1982 ◽  
Vol 99 (1) ◽  
pp. 64-71 ◽  
Author(s):  
Jens Faber ◽  
lb Bo Lumholtz ◽  
Carsten Kirkegaard ◽  
Kaj Siersbæk-Nielsen ◽  
Thorkild Friis
Keyword(s):  
Radioactive Iodine ◽  
Single Injection ◽  
Kinetic Studies ◽  
Acid Precipitation ◽  
Relative Difference ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Minor Degree ◽  
A Minor

Abstract. A method based on the principle of gel separation followed by antibody extraction (GSAE) has been developed for isolation of radioactive thyroxine (T4), 3,5,3'-triiodothyronine (T3), 3,3',5'-triiodothyronine (rT3), 3,3'-diiodothyronine (3,3'-T2), 3',5'-diiodothyronine (3',5'-T2) and 3'-monoiodothyronine (3'-T1) in serum. This method was used for the estimation of the metabolic clearance rate (MCR) of the iodothyronines using the single injection, non-compartmental approach, and was compared to the conventional trichloroacetic acid precipitation/ethanol extraction (TCA-E) technique. The GSAE method excluded the co-determination of radioactive iodine and iodoproteins, whereas the co-determination of radiolabelled daughter iodothyronines was found negligible. The relative difference of duplicate estimations of MCR was approximately 10%. Using the TCA-E method for isolation of tracer, the MCR of T4, T3 and rT3 was underestimated to a minor degree (20%), whereas the MCRs of 3,3'-T2, 3',5'-T2 and 3'-T1 were 20–40% of those estimated by the GSAE method. In conclusion the GSAE method was found suitable for kinetic studies of iodothyronines, whereas the TCA-E method cannot be used for turnover studies of 3,3'-T2, 3',5'-T2 or 3'-T1.

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