Question

Table 1. Selected Structural Data for Selected Titanocenes Mi-Ti-M2 cmpd angle (deg) Ti-M distance (A) [{Ti(-CsHMeu-72:7-CsMes)}]' 141 2.0515(9), 2.0231(9) Ti(y-CsMes)a[72-{C(SnMe3)}2}” 141 . 2.115(14) Tin-CgMes/27-{C(SiMes)}} 139 2.118, 2.109 Tim-CsHs)z[y-{C(SiMe3)CPh}}' 139 2.115-2.117(14) (Ti(y-CsMesz(u-N2)) 145-146 2.061-2.071 [Ti(79-CsMes)2(72-C2H)] 144 2.092(5) [Ti(nS-CsMes)(CO)216 148 2.06, 2.07 [Ti(79-CsHs)2(PF3)2]? 137, 138 2.012-2.020 [Ti(79-CSHMe)zdrape] 135 2.039, 2.052 [Ti(7»-CsHs) (PMezh] 133, 134 [Ti(-Cp)2] 2.049-2.062(14) 180 [Ti(79-Cp)C13718 2.018(4) 2.027

Based on the table, rationalize differences in the Ti-M bond distances in Cp2Ti(PF3)2 & Cp2Ti(PMe3)2

Answer 1

In Cpg Ti (PF3) & Cpg Ti (Pme 3)2, Pf3 and pMej are spectator ligands. Spectator Ligandy & o bablon i tontotoo la Spectator ligands are those ligands which directly increases or decreases the election Vidensitys on metal h onor words acceptor i series of spectator ligands not > c> co > P(Cf) > Pf32 NC > P > PEOPh > PCOR)3 > P Phz > PR3 > CN from the above given series it is clear that PF, is a strong n-acceptor than Pmez 80 it accepts election to its empty o orbital of Phosphorous Mence back bonding takes place which results the Ti-M band dist- -ance Shorter in C. Ti (PE) than T . Cpg Tilp meg .