Bridged calix[4]arenes; X-ray crystal and molecular structures and spectroscopic studies

Author(s):  
Volker Böhmer ◽  
Helmut Goldmann ◽  
Walter Vogt ◽  
Erich F. Paulus ◽  
Fred L. Tobiason ◽  
...  
1998 ◽  
Vol 76 (12) ◽  
pp. 1827-1835 ◽  
Author(s):  
Ivor Wharf ◽  
Ryszard Wojtowski ◽  
Carol Bowes ◽  
Anne-Marie Lebuis ◽  
Mario Onyszchuk

Complete far-IR and Raman data (<400 cm-1) are reported for triphenyltin azide (1) as well as for adducts Ph3SnN3·L (L = hexamethylphosphoramide (HMPA), triphenylphosphine oxide, pyridine-N-oxide, 4-picoline-N-oxide, or pyridine). The small changes in v(Sn-N3) noted on going from (1) to the adducts, as well as solid-state 119Sn nmr data, indicate that (1), like the adducts, has five-coordinate tin atoms. X-ray analysis shows that (1) crystallizes with two different chains of five-coordinate Ph3Sn units joined by 1,3-azide bridges. In one unit, the geometry around tin is similar to that found for the monomeric HMPA adduct (2), which has trans-axial HMPA and azide ligands. The other unit in (1) has nonplanar -SnC3- groups connected by less symmetric 1,3-azide bridges and thus resembles the structure of isoelectronic triphenyltin isocyanate.Key words: triphenyltin azide, O- and N-donor adducts, far-IR/Raman, crystal structures.


1981 ◽  
Vol 34 (10) ◽  
pp. 2139 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
AH White

The preparation of a series of novel compounds of general formula [Ni5L4(NO2)8(OH)2] formed by ethane-1,2-diamine or one of five N-substituted ethane-1,2-diamines (L) is described. The crystal and molecular structures of the ethane-1,2-diamine, N,N'-diethylethane-1,2-diamine and N,N-dimethylethane-1,2-diamine complexes are reported. Each compound contains a planar, pentameric arrangement of nickel(II) ions, linked by bridging hydroxide and nitrite ligands. The details of the nitrite bridges differ among the complexes, causing differences in their electronic and infrared spectra. The structural variations are probably caused by the differing steric requirements of the amine substituents.


2002 ◽  
Vol 41 (11) ◽  
pp. 2814-2816 ◽  
Author(s):  
Daniela Belli Dell'Amico ◽  
Consuelo Bradicich ◽  
Fausto Calderazzo ◽  
Alessandro Guarini ◽  
Luca Labella ◽  
...  

1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.


1981 ◽  
Vol 34 (10) ◽  
pp. 2095 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
BW Skelton ◽  
...  

The crystal and molecular structures of the compounds [Ni(py)4(ONO)2],2py, [Ni(γmpy),(ONO)2] and [Ni(prz)4(ONO)2] are reported.�All three are trans nitrito complexes, the pyridine (py) compound containing two pyridine molecules of solvation. The aromatic rings in the first two complexes adopt 'paddle wheel' conformations with pitch angles varying between 40 and 70�. The nitrite ions are positioned so as to minimize repulsive interactions with the amines, and it seems likely that these groups bond through oxygen rather than nitrogen because this allows a lesser degree of interligand steric interference. The amine rings in [Ni(prz)4(ONO)2] are orthogonal to the plane containing the nickel and coordinated pyrazole nitrogen atoms; the nitrito groups are disordered between two inequivalent positions, each of which involves hydrogen bonding with the pyrazole NH groups. The nitrite infrared frequencies are similar to those observed for other nickel(II) nitrito complexes except that the antisymmetric NO stretching mode of one of the groups in the pyrazole complex is much lower in energy than expected, being in the range normally associated with a nitrogen-bonded or chelated nitrite group. It is suggested that this deviation may be caused by the hydrogen bonding in the complex. The electronic spectra of the compounds yield 10Dq values of 9100 and 8500 cm-1 for the nitrite ligands in [Ni(py)4(ONO)2] and Ni(prz)4(ONO)2], respectively, placing the nitrito group towards the weaker end of the spectro-chemical series.


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