Solid-state structural chemistry of lariat ether and BiBLE cation complexes: metal-ion identity and coordination number determine cavity size

1986 ◽  
Vol 108 (14) ◽  
pp. 4078-4088 ◽  
Author(s):  
Richard D. Gandour ◽  
Frank R. Fronczek ◽  
Vincent J. Gatto ◽  
Carlo. Minganti ◽  
Rose Ann. Schultz ◽  
...  
2002 ◽  
Vol 68 (6) ◽  
pp. 3156-3158 ◽  
Author(s):  
Roni Cohen ◽  
Oded Yarden ◽  
Yitzhak Hadar

ABSTRACT The effect of Mn2+ amendment on peroxidase gene expression was studied during Pleurotus ostreatus growth on cotton stalks. Four peroxidase-encoding genes were expressed differentially and in a manner different from that observed in defined media. Mn2+ affects mnp3 expression even 2 h after its addition to the cultures, suggesting a direct effect of the metal ion on expression.


2003 ◽  
Vol 356 ◽  
pp. 203-209 ◽  
Author(s):  
Gianluca Ambrosi ◽  
Mauro Formica ◽  
Vieri Fusi ◽  
Luca Giorgi ◽  
Annalisa Guerri ◽  
...  

2010 ◽  
Vol 88 (8) ◽  
pp. 725-735 ◽  
Author(s):  
Adeeb Al-Sheikh Ali ◽  
Judy Cipot-Wechsler ◽  
Sarah M. Crawford ◽  
Omar Selim ◽  
Rhonda L. Stoddard ◽  
...  

The first series of alkali dipyrrinato complexes is reported, encompassing lithium, sodium, and potassium salts of meso-unsubstituted and meso-aryl-substituted derivatives. By varying the substituents at the meso position, the intermolecular distance between the two nitrogen atoms and thus the κ2-N,N-bidentate bite angle was altered, as confirmed by comparison of crystallographic structures of dipyrrin free-bases in the solid-state. The mode of bonding varies as the ionic radius of the metal ion increases: solid-state structures reveal lithium to be accommodated in the plane of the dipyrrinato unit, whilst sodium is accommodated out of plane. The reactivity of analogous lithium, sodium, and potassium dipyrrinato complexes increases as the ionic radius of the metal ion increases, in keeping with the concept that the complexes tend towards an increasingly ionic nature as the size of the alkali metal increases.


2005 ◽  
Vol 277-279 ◽  
pp. 708-719
Author(s):  
Chang Seop Lee ◽  
Hee Jung Lee ◽  
Sung Woo Choi ◽  
Jahun Kwak ◽  
Charles H.F. Peden

A series of cation exchanged Y-zeolites were prepared by exchanging cations with various alkali (M+, M= Li, Na, K, Cs) metals. The structural and catalytic properties of the alkali metal exchanged Y-zeolites have been investigated by a number of analytical techniques. Comparative elemental analyses were determined by an Energy Dispersive Spectroscopy X-ray (EDS), X-ray Photoelectron Spectroscopy (XPS), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) and X-ray Fluorescence (XRF) before and after cation substitution. The framework and non-framework Al coordination and the Si/Al ratios of the Y-zeolites were investigated by MAS Solid-State Nuclear Magnetic Resonance (NMR) spectroscopy. The Al NMR spectra were characterized by two 27Al resonance signals at 12 and 59 ppm, indicating the presence of the non-framework and framework Al respectively. The intensities of these resonances were used to monitor the amount of the framework and non-framework Al species in the series of exchanged zeolites. The 29Si NMR spectra were characterized by four resonance signals at -79, -84, -90, and -95 ppm. Changing the alkali metal cations in the exchanged Y-zeolites significantly altered the extent of the octahedral/tetrahedral coordination and the Si/Al ratio. The Fourier Transform Infrared spectra of the CO2 adsorbed on to the exchanged Y-zeolites showed a low frequency shift, as the atomic number of the exchanged alkali metal increased. In addition, the catalytic activity of these samples for NOx reduction were tested in combination with a non-thermal plasma technique and interpreted based on the above structural and spectroscopic information.


2004 ◽  
Vol 1 (1) ◽  
pp. 110-115
Author(s):  
Baghdad Science Journal

We found that 4,5- diphenyl- 3(2- propynyl) thio- 1??-triazole [1? forms a complex with Pd (11) ion of ratio 1:1 which absorbs light in CH2CI2 at 400 nm, and 4,5- diphenyl- 3(2- propenyl) thio- 1,2,4- triazole [II] forms complexes with Pd (II) ion of ratio 1:1 which absorbs light at 390 nm, and of ratio 2:1 which absorbs light at 435 nm. On the other hand, we found that the new derivative 4- phenyl- 5( p- amino phenyl) -3- mercapto- 1,2,4- triazole ?111? forms complexes with Cu (II) ion of the ratio 1:1 which absorbs light at 380 nm, with Ni (II) ion of the ratio 3:1 which absorbs light at 358 nm; and with Co (11) ion of the ratio 3.2:1 which absorbs light at 588 nm. The ratio of the complexes were determined by measuring the electronic spectra of the complexes in CH2G2 and (CH^NCHO at different concentrations ofthe ligands and f?xed ' •' of the metal ion in every case, then applying the molar ratio plots on the data. Our results were confirmed by precipitating most ofthe above complexes in solid state, and then each complex was analyzed elementally.


2002 ◽  
Vol 41 (12) ◽  
pp. 3183-3190 ◽  
Author(s):  
M. Tyler Caudle ◽  
Jason B. Benedict ◽  
Charles K. Mobley ◽  
Nicholas A. Straessler ◽  
Thomas L. Groy

CrystEngComm ◽  
2019 ◽  
Vol 21 (21) ◽  
pp. 3273-3279 ◽  
Author(s):  
Bingjia Yan ◽  
Peter N. Horton ◽  
Andrea E. Russell ◽  
Christopher J. Wedge ◽  
Simon C. Weston ◽  
...  

Water molecules play a key structure-organising role in the crystallisation of 15-crown-5 complexes of lithium and sodium TCNQ in the presence of excess TCNQ0.


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