Synthesis of star-shaped poly(lactide)s, poly(valerolactone)s and poly(caprolactone)s ROP catalyzed by N-donor tin(ii) cations and comparison of their wetting properties with linear analogues.

In this study, we report the use of N-coordinated tin(ii) cations [L→Sn(HO)][OTf]·THF (1) and [L→SnCl][SnCl] (2) (L = 1,2-(CHN-2-CH = N)CHCH) as efficient ROP catalysts, which, in combination with benzyl alcohol, afford well-defined linear poly(ε-caprolactone) (PCL) and poly(δ-valerolactones) (PVL) an activated monomer mechanism (AMM). Thanks to the versatility of complexes 1 and 2 as catalysts, star-shaped PCL, PVL and PLA were also prepared using three-, four-, five- and six-functional alcohols. The number of arms was determined by SEC-MALS-Visco analysis.

Tin(II) cations stabilized by non-symmetric N,N',O-chelating ligands: synthesis and stability.

A series of novel non-symmetric neutral N,N',O-chelating ligands derived from the α-iminopyridine 2-(C(R)N(CH-2,6-iPr))-6-(RRPO)CHN (L1: R = H, R = R = Ph; L2: R = Me, R = R = Ph; L3: R = H; R = Ph, R = EtO; L4: R = Me, R = Ph, R = EtO; L5: R = H, R = R = iPrO; L6: R1 = Me, R = R = iPrO) were synthesized. Ligands L1-6 were reacted with SnCl and Sn(OTf) with the aim of studying the influence of different RRPO functional groups on the Lewis base mediated ionization of SnCl and Sn(OTf). While all ligands L1-6 provided the corresponding ionic tin(II) complexes [L1-6 → SnCl][SnCl] (1-6), only ligands L1, L4 and L6 were able to stabilize tin(II) dications [L1,4,6 → Sn(HO)][OTf] (7-9).

N-Donor stabilized tin(II) cations as efficient ROP catalysts for the synthesis of linear and star-shaped PLAs the activated monomer mechanism.

α-Iminopyridine ligands L (2-(CHN(CH-2,4,6-Ph))CHN), L (2-(CHN(CH-2,4,6-Bu))CHN) and L (1,2-(CHN-2-CHN)CHCH) differing by the steric demand of the substituent on the imine CHN group and by the number of donating nitrogen atoms were utilized to initiate a Lewis base mediated ionization of SnCl in an effort to prepare ionic tin(II) species [L → SnCl][SnCl]. The reaction of L and L with SnCl led to the formation of neutral adducts [L → SnCl] (2) and [L → SnCl] (3). The preparation of the desired ionic compounds was achieved by subsequent reactions of 2 and 3 with an equivalent of SnCl or GaCl.

Synthesis and Application of Monomeric Chalcogenolates of 13 Group Elements.

Utilization of the N,C,N-chelating ligand L (L={2,6-(Me NCH ) C H } ) in the chemistry of 13 group elements provided either N→In coordinated monomeric chalcogenides LIn(μ-E ) (E=S, Se) with unprecedented InE inorganic ring or monomeric chalcogenolates LM(EPh) (M=Ga, In). Complex LGa(SePh) was selected as the most suitable single source precursor (SSP) for the deposition of amorphous semiconducting GaSe thin films using spin coating method.