Contrasting Reactivity of 2-Mesityl-1,8-Naphthyridine (Mes-NP) with Singly-Bonded [RhII–RhII] and [RuI–RuI] Compounds

2011 ◽  
Vol 64 (5) ◽  
pp. 583 ◽  
Author(s):  
Biswajit Saha ◽  
S. M. Wahidur Rahaman ◽  
Arup Sinha ◽  
Jitendra K. Bera
Keyword(s):  
Alcohol Oxidation ◽  
Moderate Activity ◽  
Steric Strain ◽  
X Ray ◽  
In Trans ◽  
In Cis ◽  
Olefination Reactions

Reaction of cis-[Rh2(CH3COO)2(CH3CN)6](BF4)2 with two equivalents of 2-mesityl-1,8-naphthyridine (Mes-NP) affords trans-[Rh2(CH3COO)2(Mes-NP)2](BF4)2 (1). X-ray structure reveals weak Rh–C(ipso) interaction, and a short Rh–Rh distance. The same ligand, in contrast, oxidatively cleaves the Ru–Ru bond in cis-[Ru2(CO)4(CH3CN)6](BF4)2 and results in trans-[Ru(Mes-NP)2(CH3CN)2](BF4)2 (2). Both compounds adopt trans geometry to relieve the steric strain. Compound 2 exhibits moderate activity for the alcohol oxidation and aldehyde olefination reactions.

Surprising Insights in the Various Molecular Structures of Hypercoordinate Bis(oxinato)silicon Complexes

2005 ◽  
Vol 60 (10) ◽  
pp. 1054-1064 ◽  
Author(s):  
Jörg Wagler ◽  
Michael Schley ◽  
Daniela Gerlach ◽  
Uwe Böhme ◽  
Erica Brendler ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Spectroscopic Analysis ◽  
Molecular Structures ◽  
Silicon Compounds ◽  
X Ray ◽  
In Trans ◽  
Coordination Patterns ◽  
In Cis ◽  
Cp Mas Nmr ◽  
C Nmr

The syntheses of two cyclic diorganosilicon enamines =CH2) [R = Ph (2a), Me (2b)] are described. These compounds react with 8-oxyquinoline leading to bis(oxinato)silicon complexes RPhSi(oxinate)2 [R = Ph (5a), Me (5b)]. Their X-ray structures reveal hexacoordination of the Si atom with the monodentate substituents in cis-positions and N atoms as well as O atoms in trans-positions.In crystalline dimethylbis(oxinato)silicon, Me2Si(oxinate)2 (7), the silicon atom is only bicapped tetrahedrally coordinated, while for dichlorobis(oxinato)silicon, Cl2Si(oxinate)2 (8), there is an octahedral coordination of the Si atom with chlorine atoms in trans-positions. This conclusion is based on the results of spectroscopic analysis (IR, 29Si CP/MAS NMR) as well as quantum chemical calculations. The first example of a silicon-bis-oxinate with the N→Si dative bonds in a trans-arrangement has been detected in the hexacoordinate silicon tris-chelate (oxinate)2Si(PhN-CH2CH2-NPh) (11). Its configuration was proven by X-ray structure analysis. Thus, for hexacoordinate bis(oxinato)silicon compounds three new architectures were found which complement the previously established building pattern of the N,N’-cis-O,O’-trans-bis(oxinato)silicon complexes.The mer-tris(oxinato)siliconium cation (9+) (its configuration being proven by 1H and 13C NMR spectroscopy) features at least three coordination patterns with (O,O;N,N)-cis,cis-, -cis,trans- as well as -trans,cis-arrangements of two oxinate ligands.

Supersilylverbindungen des Phosphors, V [1]. Darstellung, Struktur und Reaktivität des Pentaphosphids (tBu3Si)3P5Na2 und des Pentaphosphans (tBu3Si)3P5[2] / Supersilyl Compounds of Phosphorus, V [1]. Preparation, Structure, and Reactivity of the Pentaphosphide (tBu3Si)3P5Na2 and the Pentaphosphane (tBu3Si)3P5 [2]

1998 ◽  
Vol 53 (9) ◽  
pp. 1004-1014 ◽  
Author(s):  
Nils Wiberg ◽  
Angelika Wörner ◽  
Hans-Wolfram Lerner ◽  
Konstantin Karaghiosoff ◽  
Heinrich Nöth
Keyword(s):  
Structural Analysis ◽  
Molar Ratio ◽  
Trans Position ◽  
X Ray ◽  
Nmr Data ◽  
In Trans ◽  
In Cis

The orange THF adduct (tBu3Si)3P5Na2 (THF)4 of the pentaphosphide (tBu3Si)3P5Na2 (3) has been prepared, (i) by protolysis of the tetraphosphide (tBu3Si)2P4Na2(THF)n (2) with CF3CO2H in THF (molar ratio 2 : 1 ) , (ii) by dissolving crystalline 2 in toluene, and (iii) by the reaction of P4 with tBu3SiNa(THF)2 in benzene (molar ratio 1 : 4). According to an X-ray structural analysis, the THF adduct of 3 contains a P3 ring with two PNa(SitBu3) substituents in cis position and one SitBu3 substituent in trans position to the former groups. The protolysis of 3 with CF3CO2H leads to the pentaphosphane P5H2(SitBu3)3 (9), the silylation of 3 with Me2SiCl2 to the pentaphosphane P5 (SiMe2)(SitBu3)3 (10), and the oxidation of 3 with C2(CN)4 to the pentaphosphane P5(SitBu3)3 (5). The structures of 3,5,9, and 10 have been assigned from 31P and 29Si NMR data. The pentaphosphane 5 contains a hitherto unknown P5 backbone of a P3 ring anellated with a P4 ring.

The Crystal and Molecular Structure of Dichloro Monothiodibenzoylmethanato Indium Monothiodibenzoylmethane InCl2L(LH)

1986 ◽  
Vol 41 (10) ◽  
pp. 1219-1222 ◽  
Author(s):  
Anil K. Mishra ◽  
Vishnu D . Gupta ◽  
Heinrich Nöth
Keyword(s):  
Molecular Structure ◽  
Hydrogen Atom ◽  
Structure Analysis ◽  
Sodium Acetate ◽  
Crystal And Molecular Structure ◽  
Trans Position ◽  
Hydrogen Bridge ◽  
X Ray ◽  
In Trans ◽  
In Cis

Abstract Indium trichloride reacts with 2 moles of monothiodibenzoylm ethane (LH) in the presence of sodium acetate to yield In Cl2L(LH). According to an X-ray structure analysis the molecule possesses a hexacoordinated indium atom with two chlorine atoms in cis position and two sulfur atoms in trans position. The symmetry of the molecule is C2 imposed by a crystallographic twofold axis. The unique hydrogen atom , assumed to form an intermolecular hydrogen bridge between oxygen atoms could not be detected in the structure analysis.

Syntheses, Structures and Luminescence Properties of Two Cd(II) Complexes Based on 2-((1H-1,2,4-Triazol-1-yl)methyl)-1H-benzimidazole and Aromatic Polycarboxylate Ligands

2012 ◽  
Vol 67 (8) ◽  
pp. 783-790 ◽  
Author(s):  
Xiuxiu Wang ◽  
Xiao Han ◽  
Qiao ◽  
Guanghua Jin ◽  
Xiangru Meng
Keyword(s):  
Room Temperature ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
Trans Conformation ◽  
X Ray ◽  
Carboxylate Groups ◽  
Benzenedicarboxylic Acid ◽  
In Trans ◽  
2D Structure ◽  
In Cis

Two new Cd(II) complexes, {[Cd(m-bdc)(tmb)(H2O)]·CH3OH}n (1) and {[Cd(t-bdc)(tmb)(H2O)] ·2H2O·DMF}n (2), have been prepared by using 2-((1H-1,2,4-triazol-1-yl)methyl)-1Hbenzimidazole (tmb) as a ligand in the presence of 1,3-benzenedicarboxylic acid (m-H2bdc) or 1,4-benzenedicarboxylic acid (t-H2bdc). Single-crystal X-ray diffraction exhibits that complex 1 displays a 2D structure constructed by tmb ligands in trans conformation and carboxylate groups in a chelating mode. The 2D structure of complex 2is different from that of 1, in that the tmb ligands are in cis conformation, and the carboxylate groups are in both unidentate or chelating coordination mode at the Cd(II) centers. The luminescence properties of 1and 2in the solid state at room temperature have been studied

Author response for "TIM-3 and CEACAM1 do not interact in cis and in trans"

2020 ◽  
Author(s):  
Annika De Sousa Linhares ◽  
Florian Kellner ◽  
Sabrina Jutz ◽  
Gerhard J. Zlabinger ◽  
Hans-Joachim Gabius ◽  
...  
Keyword(s):  
Author Response ◽  
In Trans ◽  
In Cis

scholarly journals A novel transvection phenomenon affecting the white gene of Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 126 (1) ◽  
pp. 167-176
Author(s):  
D Gubb ◽  
M Ashburner ◽  
J Roote ◽  
T Davis
Keyword(s):  
Drosophila Melanogaster ◽  
Homologous Chromosome ◽  
Tandem Duplication ◽  
Gamma Ray ◽  
Insertion Site ◽  
Hairpin Loop ◽  
Homologous Chromosomes ◽  
Inverted Order ◽  
In Trans ◽  
In Cis

Abstract The zeste mutation of Drosophila melanogaster suppresses the expression of white genes in the eye. This suppression is normally dependent on there being two copies of w+ located close to each other in the genome--they may either be in cis (as in a tandem duplication of w+) or in trans, i.e. on homologous chromosomes. Duplicated w+ genes carried by a giant transposing element, TE146(Z), are suppressed by z whether they are in direct (tandem) or inverted order. The tandem form of the TE is very sensitive to a rearrangement on the homologous chromosome--many rearrangements with breakpoints "opposite" the TE's insertion site prevent the interaction between the white genes on a z background. These aberrations act as dominant suppressors of zeste that are specific to the tandemly duplicated form of TE146(Z). The inverted form of the TE146(Z) presumably pairs as a hairpin loop; this is more stable than the tandem form by the criterion that its zeste phenotype is unaffected by any of the aberrations. This effect of rearrangements has been used as the basis for a screen, gamma-ray induced aberrations with at least one breakpoint opposite the TE site were recovered by their suppression of the zeste phenotype.

scholarly journals Determinants of Chromosome Architecture: Insulator Pairing in cis and in trans

PLoS Genetics ◽  
2016 ◽  
Vol 12 (2) ◽  
pp. e1005889 ◽  
Author(s):  
Miki Fujioka ◽  
Hemlata Mistry ◽  
Paul Schedl ◽  
James B. Jaynes
Keyword(s):  
Chromosome Architecture ◽  
In Trans ◽  
In Cis

scholarly journals Means of self-preservation: how an intrinsically disordered ubiquitin-protein ligase averts self-destruction

2013 ◽  
Vol 24 (7) ◽  
pp. 1041-1052 ◽  
Author(s):  
Eric K. Fredrickson ◽  
Sarah V. Clowes Candadai ◽  
Cheuk Ho Tam ◽  
Richard G. Gardner
Keyword(s):  
Substrate Binding ◽  
Proteasomal Degradation ◽  
Ubiquitin Protein Ligase ◽  
Intrinsically Disordered ◽  
Ubiquitin Conjugating Enzyme ◽  
In Trans ◽  
Key Residues ◽  
In Cis ◽  
Self Protection ◽  
Disordered Regions

Ubiquitin-protein ligases (E3s) that ubiquitinate substrates for proteasomal degradation are often in the position of ubiquitinating themselves due to interactions with a charged ubiquitin-conjugating enzyme (E2). This can mediate the E3’s proteasomal degradation. Many E3s have evolved means to avoid autoubiquitination, including protection by partner or substrate binding, preventative modifications, and deubiquitinating enzyme reversal of ubiquitination. Here we describe another adaptation for E3 self-protection discovered while exploring San1, which ubiquitinates misfolded nuclear proteins in yeast for proteasomal degradation. San1 is highly disordered in its substrate-binding regions N- and C-terminal to its RING domain. In cis autoubiquitination could occur if these flexible regions come in proximity to the E2. San1 prevents this by containing no lysines in its disordered regions; thus the canonical residue used for ubiquitin attachment has been selectively eliminated. San1’s target substrates have lost their native structures and expose hydrophobicity. To avoid in trans autoubiquitination, San1 possesses little concentrated hydrophobicity in its disordered regions, and thus the that feature San1 recognizes in misfolded substrates has also been selectively eliminated. Overall the presence of key residues in San1 have been evolutionarily minimized to avoid self-destruction either in cis or in trans. Our work expands the ways in which E3s protect themselves from autoubiquitination.

The Effect of Heterologous Insertions on Gene Conversion in Mitotically Dividing Cells in Drosophila melanogaster

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 249-258
Author(s):  
Angela M Coveny ◽  
Tammy Dray ◽  
Gregory B Gloor
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Conversion ◽  
Strand Break ◽  
Double Strand Break ◽  
P Element ◽  
Double Strand Break Repair ◽  
Break Site ◽  
In Trans ◽  
Break Repair ◽  
In Cis

Abstract We examined the influence that heterologous sequences of different sizes have on the frequency of double-strand-break repair by gene conversion in Drosophila melanogaster. We induced a double-strand break on one X chromosome in female flies by P-element excision. These flies contained heterologous insertions of various sizes located 238 bp from the break site in cis or in trans to the break, or both. We observed a significant decrease in double-strand-break repair with large heterologous insertions located either in cis or in trans to the break. Reestablishing the homology by including the same heterologous sequence in cis and in trans to the double-strand break restored the frequency of gene conversion to wild-type levels. In one instance, an allelic nonhomologous insertion completely abolished repair by homologous recombination. The results show that the repair of a double-strand break by gene conversion requires chromosome pairing in the local region of the double-strand break.

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