Amphiphilic iron(ii) complexes with short alkyl chains – crystal packing and spin transition properties

2014 ◽  
Vol 38 (5) ◽  
pp. 1965-1972 ◽  
Author(s):  
Stephan Schlamp ◽  
Katja Dankhoff ◽  
Birgit Weber
Keyword(s):  
Crystal Packing ◽  
Spin Transition ◽  
Alkyl Chains

Structural, magnetic and Mössbauer spectroscopic studies of the [Fe(3-bpp)2](CF3COO)2 complex: role of crystal packing leading to an incomplete Fe(ii) high spin ⇋ low spin transition

CrystEngComm ◽  
2021 ◽  
Vol 23 (15) ◽  
pp. 2854-2861
Author(s):  
Kristian Handoyo Sugiyarto ◽  
Djulia Onggo ◽  
Hiroki Akutsu ◽  
Varimalla Raghavendra Reddy ◽  
Hari Sutrisno ◽  
...  
Keyword(s):  
High Spin ◽  
Crystal Packing ◽  
Spin Transition ◽  
Spectroscopic Studies ◽  
Mononuclear Complex

Mononuclear complex [Fe(3-bpp)2](CF3COO)2 exhibits a thermal (HS + HS) ⇋ (HS + LS) transition at ∼226 K which is not associated with any crystallographic transition.

Spin Transition Induced by Mesophase Transition in the Cobalt(II) Compounds with Branched Alkyl Chains

2009 ◽  
Vol 509 (1) ◽  
pp. 309/[1051]-316/[1058] ◽  
Author(s):  
Shinya Hayami ◽  
Yoshihiro Kojima ◽  
Katsuya Inoue
Keyword(s):  
Spin Transition ◽  
Alkyl Chains

Preparation and Properties of Surfactant Complexes of Ruthenium(II)

1979 ◽  
Vol 32 (7) ◽  
pp. 1453 ◽  
Author(s):  
O Johansen ◽  
C Kowala ◽  
AWH Mau ◽  
WHF Sasse
Keyword(s):  
Solid State ◽  
Surface Pressure ◽  
Luminescence Intensity ◽  
Crystal Packing ◽  
Emission Spectra ◽  
Quantum Yields ◽  
Alkyl Chains ◽  
Pressure Area ◽  
Bimolecular Quenching ◽  
Chain Lengths

New surfactant complexes RuM2L2+ have been prepared where M is 2,2'-bipyridyl or o-phenanthro- line and L is one of the 4-alkyl-4'-methyl-2,2'-bipyridyls (8a)-(8e), or one of the 4,4'-dialkyl-2,2'- bipyridyls (9a)-(9e), or 1,1'-(2,2'-bipyridyl-4,4'-diyl)bis(nonadecan-1-one). This diketone was pre- pared from 2,2'-bipyridyl-4,4'-dicarboxylic acid and dioctadecylcadmium; the dialkylbipyridyls were obtained by condensing 4,4'-dimethyl-2,2'-bipyridyl with 5-alkylthiopen-2-carbaldehydes, followed by desulfurization with W5 Raney nickel. Several properties of the new complexes have been compared with those of bis(2,Y-bipyridyl)(dioctadecyl 2,2'-bipyridyl-4,4'-dicarboxy1ate)ruthenium dication (2). Monolayers have been prepared and characterized by surface-pressure area curves; film com- pressibilities and stabilities are related to the lengths of the alkyl chains and to subphase composition. Absorption and emission spectra have been examined. The quantum yields and lifetimes of emission are similar in alcohol and water; with monolayer assemblies they are dependent on subphase com- position, and in the solid state they vary between 0.03-0.18 for Φ and 0.5-1.5 μs for τ, according to the chain lengths, which appear to affect crystal packing. Oxygen quenched the luminescence of solutions and supported monolayers reversibly; Stern- Volmer constants and bimolecular quenching constants are given for: diester complex (2), diketone complex (6), dialkylbipyridyl complexes (5). Except with (2) the original luminescence intensity was restored by drying. Hydrogen was not detected following irradiation with visible light of supported monolayers of pure complexes immersed in water.

Spin Transition at the Mesophase Transition Temperature in a Cobalt(II) Compound with Branched Alkyl Chains

2007 ◽  
Vol 46 (19) ◽  
pp. 7692-7694 ◽  
Author(s):  
Shinya Hayami ◽  
Reiko Moriyama ◽  
Aya Shuto ◽  
Yonezo Maeda ◽  
Kazuchika Ohta ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Spin Transition ◽  
Alkyl Chains

scholarly journals Iron(III) Azadiphenolate Compounds in a New Family of Spin Crossover Iron(II)–Iron(III) Mixed-Valent Complexes

2019 ◽  
Vol 5 (2) ◽  
pp. 37 ◽  
Author(s):  
Wasinee Phonsri ◽  
David S. Macedo ◽  
Barnaby A. I. Lewis ◽  
Declan F. Wain ◽  
Keith S. Murray
Keyword(s):  
Crystal Structures ◽  
Spin Crossover ◽  
Crystal Packing ◽  
Spin Transition ◽  
Double Salt ◽  
Magnetic Studies ◽  
Cationic Precursor ◽  
New Family ◽  
Double Spin ◽  
Crystal Design

A new family of mixed valent, double salt spin crossover compounds containing anionic FeIII and cationic FeII compounds i.e., [FeII{(pz)3CH}2][FeIII(azp)2]2·2H2O (4), [FeII(TPPZ)2][FeIII(azp)2]2]·H2O (5) and [FeII(TPPZ)2][FeIII(azp)2]2]·H2O·3MeCN (6) (where (pz)3CH = tris-pyrazolylmethane, TPPZ = 2,3,5,6, tetrapyridylpyrazine and azp2− = azadiphenolato) has been synthesized and characterised. This is the first time that the rare anionic spin crossover species, [FeIII(azp)2]−, has been used as an anionic component in double salts complexes. Single crystal structures and magnetic studies showed that compound 6 exhibits a spin transition relating to one of the FeIII centres of the constituent FeII and FeIII sites. Crystal structures of the anionic and cationic precursor complexes were also analysed and compared to the double salt products thus providing a clearer picture for future crystal design in double spin crossover materials. We discuss the effects that the solvent and counterion had on the crystal packing and spin crossover properties.

Stable, low-melting trans-A2B-corroles

2016 ◽  
Vol 20 (08n11) ◽  
pp. 1244-1255 ◽  
Author(s):  
Agnieszka Nowak-Król ◽  
Eleanor Fourie ◽  
Chris C. Joubert ◽  
Dorota Gryko ◽  
Daniel T. Gryko ◽  
...  
Keyword(s):  
Crystal Packing ◽  
Redox Processes ◽  
Free Base ◽  
Sufficient Time ◽  
Acid Base ◽  
Scanning Calorimetry ◽  
Straightforward Manner ◽  
Redox States ◽  
Alkyl Chains ◽  
Acid Base Equilibrium

The liquid or low-melting free base corroles (A2Bcor)H3 with cor [Formula: see text] trianionic macrocyclic core without any protons, A [Formula: see text] 4-(OC[Formula: see text]H[Formula: see text]C6F4 and B [Formula: see text] 3,4,5-(OC[Formula: see text]H[Formula: see text]C6H2 for 4 or [Formula: see text] 3,4,5-(OC[Formula: see text]H[Formula: see text]C6H2 for 5, were prepared in a straightforward manner from 3,4,5-trialkoxybenzaldehydes and a suitable dipyrrane possessing four fluorine atoms. This synthetic result paved the way to stable and at the same time liquid or low melting meso-substituted corroles. The presence of altogether eight fluorine atoms in the trans-A2B-corroles was essential to maintain corrole stability. An electrochemical study of 4 in CH2Cl showed that the behavior of this corrole is dominated by three different species in an acid base equilibrium with each other: [(A2Bcor)H2][Formula: see text], 4[Formula: see text], (A2Bcor)H3, 4 and [(A2Bcor)H4][Formula: see text], 4[Formula: see text]. Four different redox states for each of these three components could be identified in 12 separate one-electron transfer redox processes. A mechanism explaining the observed twelve redox and four chemical steps is proposed. Differential scanning calorimetry measurements have proven that if alkyl chains are long enough (C18), the corrole melts at record low temperature (63.7 [Formula: see text]C) and it is stable throughout multiple temperature variation cycles up to 300 [Formula: see text]C. Upon crystallization an initial kinetic driven crystal packing for the product is obtained that melts at 20 [Formula: see text]C, but after sufficient time has elapsed (20 h), it converts into the thermodynamically stable crystal packing form with melting point of 63.7 [Formula: see text]C, probably because of rearrangements in the alignment of the five OCH[Formula: see text]H[Formula: see text] chains in 5.

scholarly journals 2D Layer Arrangement of Solely [HS-HS] or [LS-LS] Molecules in the [HS-LS] State of a Dinuclear Fe(II) Spin Crossover Complex

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 448
Author(s):  
Fabian Fürmeyer ◽  
Luca M. Carrella ◽  
Eva Rentschler
Keyword(s):  
Crystal Structure ◽  
Spin Crossover ◽  
Crystal Packing ◽  
Spin Transition ◽  
High Spin State ◽  
Crystal Structure Analysis ◽  
Magnetic Data ◽  
The Novel ◽  
Layer Arrangement ◽  
Dinuclear Iron

Herein we report the synthesis and characterization of three new dinuclear iron(II) complexes [FeII2(I4MTD)2](F3CSO3)4 (C1), [FeII2(I4MTD)2](ClO4)4 (C2) and [FeII2(I4MTD)2](BF4)4 (C3) based on the novel ligand (I4MTD = 2,5-bis{[(1H-imidazol-4-ylmethyl)amino]methyl}-1,3,4-thiadiazole). Magnetic susceptibility measurements and single-crystal structure analysis show that the iron(II) spin centers for all complexes are in the high spin state at high temperatures. While the magnetic data of air-dried samples confirm the [HS-HS] state for C1 and C2 down to very low temperature, for C3, a gradual spin crossover is observed below 150 K. The crystal structure of C3·THF at 100 K shows that a spin transition from [HS-HS] to an intermediate state takes place, which is a 1:1 mixture of discrete [HS-HS] and [LS-LS] molecules, as identified unambiguously by crystallography. The different SCO properties of C1–C3 can be attributed to crystal packing effects in the solid state.

Spin-Transition and Ferromagnetic Interactions in Copper(II) Complexes of a 3-Pyridyl-Substituted Imino Nitroxide. Dependence of the Magnetic Properties upon Crystal Packing

1996 ◽  
Vol 35 (12) ◽  
pp. 3484-3491 ◽  
Author(s):  
Fabrice Lanfranc de Panthou ◽  
Dominique Luneau ◽  
Ryza Musin ◽  
Lars Öhrström ◽  
André Grand ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Crystal Packing ◽  
Spin Transition ◽  
Ferromagnetic Interactions ◽  
Imino Nitroxide

The low-resolution 3D-structure of porin, a channel-forming protein in E. coliouter membranes

1983 ◽  
Vol 41 ◽  
pp. 440-441
Author(s):  
A. Engel ◽  
D.L. Dorset ◽  
A. Massalski ◽  
J.P. Rosenbusch
Keyword(s):  
Crystal Packing ◽  
3D Structure ◽  
Gram Negative Bacteria ◽  
Protein Ratio ◽  
Crystal Forms ◽  
Large Molecules ◽  
Functional Studies ◽  
Voltage Dependent ◽  
Planar Membranes ◽  
Hexagonal Arrays

Porins represent a group of channel forming proteins that facilitate diffusion of small solutes across the outer membrane of Gram-negative bacteria, while excluding large molecules (>650 Da). Planar membranes reconstituted from purified matrix porin (OmpF protein) trimers and phospholipids have allowed quantitative functional studies of the voltage-dependent channels and revealed concerted activation of triplets. Under the same reconstitution conditions but using high protein concentrations porin aggregated to 2D lattices suitable for electron microscopy and image processing. Depending on the lipid-to- protein ratio three different crystal packing arrangements were observed: a large (a = 93 Å) and a small (a = 79 Å) hexagonal and a rectangular (a = 79 Å b = 139 Å) form with p3 symmetry for the hexagonal arrays. In all crystal forms distinct stain filled triplet indentations could be seen and were found to be morphologically identical within a resolution of (22 Å). It is tempting to correlate stain triplets with triple channels, but the proof of this hypothesis requires an analysis of the structure in 3 dimensions.

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