Extending Distannoxane Double Ladders Using Rigid Spacers:  A Double Ladder with Eight Chiral Tin Atomsand a Twist!

Abstract

The new bulky silicon-containing ditin precursor p-(RCl2SnCH2SiMe2)2C6H4 (R = CH2SiMe3 (4)) has been synthesized and further reacted to form a unique double ladder {[p-(R(Cl)SnCH2SiMe2)2C6H4]O}4 (6). The two layers within 6 are twisted with respect to one another, resulting in a helical motif and a total absence of molecular symmetry so that there are eight chiral tin atoms within the system. The structure is compared to the double ladder {[m-(R(Cl)SnCH2CH2)2C6H4]O}4 (11), which was prepared from the less sterically demanding ditin precursor m-(RCl2SnCH2CH2)2C6H4 (10). The two layers within 11 are parallel, and the molecule contains only two kinds of tin atom.

Chiral self-assembly of methyltin(IV)-naproxenates: Combining dative Sn–O bonds, secondary Sn⋯O interactions and C–H⋯O hydrogen bonding to make an inter-helical meander-shaped network and a cross-linked Z-shaped ribbon

“…It should be noted here that according to the Q, h and u puckering parameters (Table 4) (1)°with respect to one another. To the best of our knowledge only one report has appeared so far for a double ladder structure containing eight different chiral tin centers [54]. (Table 2).…”

Crystallographic report: 1,4‐Bis[bis(trimethylsilyl)methyl‐dichlorostannylmethyldimethylsilyl]benzene, p‐{[(Me3Si)2CH]Sn(Cl)2CH2SiMe2}2C6H4

“…1 The crystal structure determination shows an`S' conformation for the centrosymmetric molecule ( Fig. 1).…”

Macrocyclic organotin(IV) carboxylates based on benzenedicarboxylic acid derivatives: Syntheses, crystal structures and antitumor activities

“…Intermolecular Sn/O interactions exist between Sn (Sn3 for 4, Sn4 for 5 and Sn1 for 6) and O (ethanolic oxygen O11B for 4, ethanolic oxygen O11B for 5 and carbonylic oxygen O5B for 6) at 3.017, 2.903 and 3.393 Å, in which the ethanolic oxygen shows stronger coordination than carbonylic oxygen. The influence of the intermolecular O atoms is so strong that it causes the expansion of the CeSneC angle [C26eSn3eC22 140.9(2) for 4, C49eSn4eC53 138.11 (15) for 5 and C47eSn1eC51 134.2(3) for 6]. If these oxygen atoms can be considered as bonding, each tin atom (Sn3 for 4, Sn4 for 5 and Sn1 for 6) is seven-coordinated.…”