Search results for "Length"

Bgl II restriction fragment length polymorphism of human complement C4A gene coincides with BF*F allele of factor B.

1988

Synthesis and crystal structure of the low-spin iron(II) complex [Fe(bpym)3](ClO4)2·1/4H2O (bpym=2,2′-bipyrimidine)

1997

Abstract Single crystals of the mononuclear iron(II) complex of formula [Fe(bpym)3](ClO4)2·1/4H2O (bpym=2,2′-bipyrimidine) have been prepared and characterized crystallographically. The complex is monoclinic, P21/c, a=13.688(5), b=19.391(6), c=11.554(5) A, β=102.22(3)°, V=2997(2) A3, Z=4, R=0.063 and Rw=0.068. The structure analysis reveals a distorted octahedral geometry around the iron atom. The average Fe–N bond length and N–Fe–N bidentate angle are 1.970(5) A and 81.0(1)°, respectively. The value of the Fe–N distance and that of the room temperature magnetic moment are in agreement with its singlet 1A1 ground state.

Synthesis, crystal structure and magnetic properties of the spin crossover system [Fe(pq)3]2+

2008

Abstract Three new compounds formulated (ClO4)2[Fe(pq)3] (1), (BF4)2[Fe(pq)3] · EtOH (2) and {(ClO4)[MnCr(C2O4)3][Fe(pq)2(H2O)2]} (3), where pq is 2,2′-pyridylquinoline, have been synthesised and characterised. Despite the different crystal packing exhibited by 1 and 2, the cationic species [Fe(pq)3]2+ are structurally quite similar. At 293 K, the Fe–N bond lengths are characteristic of the iron(II) in the high-spin state. In contrast to 1, 2 undergoes a continuous spin transition. Indeed, at 95 K its structure experiences a noticeable change in the Fe–N bonds and angles, i.e. the Fe–N bonds shorten by 0.194 A on the average. The magnetic behaviour confirms that 1 is fully high-spin in the …

Synthesis and Physical Properties of K4[Fe(C5O5)2(H2O)2](HC5O5)2·4H2O (C5O52– = Croconate): A Rare Example of Ferromagnetic Coupling via H-bonds

2012

The reaction of the croconate dianion (C(5)O(5))(2-) with a Fe(III) salt has led, unexpectedly, to the formation of the first example of a discrete Fe(II)-croconate complex without additional coligands, K(4)[Fe(C(5)O(5))(2)(H(2)O)(2)](HC(5)O(5))(2)·4H(2)O (1). 1 crystallizes in the monoclinic P2(1)/c space group and presents discrete octahedral Fe(II) complexes coordinated by two chelating C(5)O(5)(2-) anions in the equatorial plane and two trans axial water molecules. The structure can be viewed as formed by alternating layers of trans-diaquabis(croconato)ferrate(II) complexes and layers containing the monoprotonated croconate anions, HC(5)O(5)(-), and noncoordinated water molecules. Both …

Syntheses, Crystal Structures, and Magnetic Properties of the Oxalato-Bridged Mixed-Valence Complexes [FeII(bpm)3]2[FeIII2(ox)5]·8H2O and FeII(bpm)3N…

2001

The preparation and crystal structures of two oxalato-bridged FeII-FeIII mixed-valence compounds, [FeII(bpm)3]2[FeIII2(ox)5].8H2O (1) and FeII(bpm)3Na(H2O)2FeIII(ox)(3).4H2O (2) (bpm = 2,2'-bipyrimidine; ox = oxalate dianion) are reported here. Complex 1 crystallizes in the triclinic system, space group P1, with a = 10.998(2) A, b = 13.073(3) A, c = 13.308(3) A, alpha = 101.95(2) degrees, beta = 109.20(2) degrees, gamma = 99.89(2) degrees, and Z = 1. Complex 2 crystallizes in the monoclinic system, space group P2(1)/c, with a = 12.609(2) A, b = 19.670(5) A, c = 15.843(3) A, beta = 99.46(1) degrees, and Z = 4. The structure of complex 1 consists of centrosymmetric oxalato-bridged dinuclear h…

Analysis of the main structural trends for biscyclometalated dinuclear rhodium compounds of general formula Rh2(O2CR)2(PC)2·2H2O

2008

Abstract A new series of biscyclometalated dinuclear rhodium (II) compounds with the general formula Rh2(O2CR)2(PC)2 · 2H2O, being PC = (C6H4)P(C6H5)2, R = CH3 (1 · 2H2O), PC = [(p-CH3 OC6H3)P(p-CH3 OC6H4)2], R = CF3 (2 · 2H2O), PC = (C6H4)P[CH(CH3)2]2, R = CH3 (3 · 2H2O) and PC = (C6H4)P(C6H5)2, R = C6F5 (4 · 2H2O) has been obtained. The crystal structures for these compounds have been determined by X-ray diffraction and the main structural trends, bond lengths, bond angles and torsion angles have been analyzed, and have also been compared with the structural parameters for different analogous complexes described previously in the literature.

Structures and Magnetic Properties of Bis(μ‐phenoxido), Bis(μ‐phenoxido)‐μ‐carboxylato and Bis(μ‐phenoxido)bis(μ‐carboxylato) Fe III Ni II Compounds …

2015

This report describes the syntheses, characterization, crystal structures and magnetic properties of five dinuclear FeIIINiII compounds derived from two Robson-type tetraiminodiphenol macrocyclic ligands H2L1 and H2L2, which are the [2+2] condensation products of 4-ethyl-2,6-diformylphenol and 1,3-diaminopropane (for H2L1) or 2,2-dimethyl-1,3-diaminopropane (for H2L2). The compositions of the compounds are [FeIII(N3)2L1NiII(H2O)2](ClO4) (1), [FeIII(benzoato)L1NiII(H2O)(μ1,3-benzoato)](ClO4) (2), [FeIII(benzoato)L2NiII(H2O)(μ1,3-benzoato)](ClO4) (3), [FeIIIL2NiII(μ1,3-acetato)2](ClO4)·H2O (4) and [FeIIIL2NiII(μ1,3-propionato)2](ClO4)·H2O (5). The bridging moieties between the two metal ions …

Über gemischte bindungen in der IV. Hauptgruppe

1984

Abstract The reaction of Ph 3 PbLi with Ph 3 SnCl or Ph 3 GeCl gives Ph 3 PbSnPh 3 and Ph 2 PbGePh 3 , respectively; there is no reaction with Ph 3 SiCl. Ph 3 SiLi reacts with Ph 3 PbCl to form a regular 1 : 1 Pb 2 Ph 6 · Si 2 Ph 6 phase. The compounds have been investigated by mass, NMR and vibrational spectra: 207 Pb NMR chemical shifts with respect to PbMe 2 −79.8 (Pb 2 Ph 6 ), −256.5 (Ph 3 PbSnPh 3 ), −271.5 ppm (Ph 3 PbGePh 3 ); stretching vibrations 112 (PbPb), 125 (PbSn), 138 cm −1 (PbGe). The crystal structures have been determined and refined to R = 0.061 (Ph 3 PbSnPh 3 , −40°C), 0.053 (Ph 3 PbGePh 3 , −50°C), 0.068 (Pb 2 Ph 6 · Si 2 Ph 6 , 20°C); bond lengths 285 (PbPb),…

Über Arsen‐haltige Heterocyclen, I. Molekül‐ und Kristallstruktur von 2‐Chlor‐1,3,6,2‐trithiarsaocan

1974

Die Struktur der Titelsubstanz (2) wurde rontgenographisch aus Diffraktometer-Einkristalldaten bestimmt und bis zu einem konventionellen R von 0.037 verfeinert. Der 8-Ring hat eine deformierte Wannenform mit transannularer 1,5-AsS-Annaherung. 2 ist dissymmetrisch, der wechselseitige Ubergang zwischen den beiden Spiegelbildisomeren wird besprochen. Die Koordination am As-Atom ist ψ-trigonal-bipyramidal mit axialen Abstanden AsCl 2.36 A, AsS 2.72 A und aquatorialen Abstanden AsS 2.25 und 2.26 A. Bekannte AsS-Abstande und Koordinationen werden diskutiert und Standardwerte fur AsS- und SbS-Abstande verschiedenen Bindungstyps ermittelt. 2 bildet ein Modell fur die Blockierung von Enzym-Proteinen…

Über Phosphor‐haltige Heterocyclen, II: Molekül‐ und Kristallstruktur von 1,2,3,4,5‐Pentaphenyl‐1λ 5 ‐phosphol‐1‐on

1976

Die Struktur der Titelsubstanz wurde rontgenographisch aus Diffraktometer-Einkristalldaten bestimmt und bis zu einem konventionellen R von 0.076 verfeinert. Der 5-ring besitzt „envelope”-Konformation. Fehlende Planaritat und Bindungslangenverteilung schliesen eine Elektronendelokalisation im λ5-Phospholsystem aus. Das Propellersystem der Phenylsubstituenten bildet eine Cs-symmetrische Doppelschneckenschraube. Die Struktur besteht aus 14-fach koordinierten Molekulen. On Heterocyclic Systems Containing Phosphorus, II: Molecular and Crystal Structure of 1,2,3,4,5-Pentaphenyl-1 λ5-phosphol-1-one The crystal structure of the title compound has been determined from single crystal X-ray data and r…