Isomorphism in monomeric 1:3 complexes of silver(I) salts with tri-p-tolylphosphine

2009 ◽  
Vol 65 (6) ◽  
pp. 699-706 ◽  
Author(s):  
Bernard Omondi ◽  
Gertruida J. S. Venter ◽  
Andreas Roodt ◽  
Reinout Meijboom
Keyword(s):  
Orthorhombic Space Group ◽  
Normal Probability Plot ◽  
Space Group ◽  
Probability Plot ◽  
Plot Analysis ◽  
Normal Probability

Reaction of silver(I) salts with three equivalents of tri-p-tolylphosphine in CH3CN resulted in a series of isomorphous complexes [AgX{P(4-MeC6H4)3}3] (X = Br, SCN, ClO4). These complexes all crystallize in the orthorhombic space group Pna21. The complexes with X = Br, SCN are distorted tetrahedral around the silver(I) atom, whereas the ClO4 − complex is distorted trigonal planar around the silver. The new complexes are compared with each other using r.m.s. overlay calculations as well as half-normal probability plot analysis and with the previously reported isomorphous chloride, bromide as well as the non-isomorphous iodide complexes.

Application of normal probability plot analysis to lutetium orthoborate factors and parameters

1971 ◽  
Vol 4 (4) ◽  
pp. 284-290 ◽  
Author(s):  
S. C. Abrahams ◽  
J. L. Bernstein ◽  
E. T. Keve
Keyword(s):  
Standard Deviation ◽  
Least Squares ◽  
Thermal Vibration ◽  
Normal Probability Plot ◽  
Lattice Constants ◽  
Probability Plot ◽  
Plot Analysis ◽  
Structure Factors ◽  
Normal Probability ◽  
Vibration Parameters

The methods of normal probability plot analysis have been applied to two nearly complete sets of structure factors (F meas) and the corresponding objectively assigned standard deviations (σF meas) obtained by diffractometer measurement with two different crystals of lutetium orthoborate. The least-squares derived positional and thermal vibration parameters are shown to be too small by a factor of 1.8, and the σF meas to be overestimated by a factor of 1.55. The two sets of F meas are found to contain a small but parallel bias. The lattice constants of rhombohedral calcite-type LuBO3 are measured as a H = 4.91538±0.00002 Å and cH = 16.21200±0.00003 Å at 298°K, with six formulas in the unit cell, space group R\overline 3c. The Lu–O distance in this six-coordinated Lu compound is 2.240±0.002 Å (corrected standard deviation). The B–O distance in the BO3 triangular groups is 1.370±0.005 Å. The characteristic Θ temperature is estimated as 446±19°K.

Concomitant polymorphic behavior of di-μ-thiocyanato-κ2 N:S;κ2 S:N-bis[bis(tri-p-fluorophenylphosphine-κP)silver(I)]

2010 ◽  
Vol 66 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Bernard Omondi ◽  
Reinout Meijboom
Keyword(s):  
Phosphine Ligands ◽  
Asymmetric Unit ◽  
Polymorphic Behavior ◽  
Tetrahedral Geometry ◽  
Normal Probability Plot ◽  
Distorted Tetrahedral Geometry ◽  
Probability Plot ◽  
Plot Analysis ◽  
Normal Probability ◽  
Dinuclear Structure

The structures of two polymorphs, both monoclinic P21/n [polymorph (I)] and P21/c [polymorph (II)], of di-μ-thiocyanato-κ2 N:S;κ2 S:N-bis[bis(tri-p-fluorophenylphosphine-κP)silver(I)] complexes have been determined at 100 K. In both polymorphs the complex has a dinuclear structure where the silver(I) coordinates to two phosphine ligands and two bridging thiocyanate anions to form complexes with distorted tetrahedral geometry. Polymorph (I) has just one half of the [Ag2(SCN)2{P(4-FC6H4)3}4] molecule at (0, ½, 0) from the origin in the asymmetric unit. Polymorph (II) has one and a half molecules of [Ag2(SCN)2{P(4-FC6H4)3}4] in the asymmetric unit; the half molecule is situated at (0, 1, ½), while the full molecule is located at (1/3, ½, 1/3) from the origin. The Ag—P bond distances range from 2.4437 (4) to 2.4956 (7) Å in both polymorphs. The Ag—S distances are 2.5773 (7) Å in (I) and 2.5457 (5), 2.5576 (5) and 2.5576 (5) Å in (II). The full molecule in polymorph (II) has slightly shorter Ag—N bond distances [2.375 (1) and 2.367 (2) Å] compared with the half molecules in both polymorphs [2.409 (2) Å in (II) and 2.395 (2) Å in (I)]. The two polymorphs are compared using r.m.s. overlay calculations as well as half-normal probability plot analysis.

Sign in / Sign up

Export Citation Format

Share Document