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Activation of H-H, Si-H, and C-H bonds through σ-bond coordination has grown in the past 30 years from a scientific curiosity to an important tool in the functionalization of hydrocarbons. Several mechanisms were discovered via which the initially σ-bonded substrate could be converted: oxidative addition, heterolytic cleavage, σ-bond metathesis, electrophilic attack, etc. The use of metal nanoparticles (NPs) in this area is a more recent development, but obviously nanoparticles offer a much richer basis than classical homogeneous and heterogeneous catalysts for tuning reactivity for such a demanding process as C-H functionalization. Here, we will review the surface chemistry of nanoparticles and catalytic reactions occurring in the liquid phase, catalyzed by either colloidal or supported metal NPs. We consider nanoparticles prepared in solution, which are stabilized and tuned by polymers, ligands, and supports. The question we have addressed concerns the differences and similarities between molecular complexes and metal NPs in their reactivity toward σ-bond activation and functionalization.

Objectives: To compare the safety and efficacy of the new cobalt-chromium bioactive stent Titan Optimax ® (Hexacath, France) with its predecessor, Titan-2 ® ., Background: The TIOMAX registry includes 784 patients who underwent percutaneous coronary intervention with these stents in 21 Spanish hospitals., Methods: Analysis of all patients in the registry without exclusion criteria, candidates for revascularization (March-2013/July-2014). Initially 273 patients received Titan-2 ® , and the next 511 received the Optimax ® after its launch., Results: Mean age was 65.8 ± 13.0 (78.1% men); 49.2% were STEACS patients (n = 322), 29.8% NSTEACS, and 27.3% had stable angina or silent ischemia. Most STEACS patients (76.4% of n = 322) were treated <24 hr after developing symptoms. All-cause death (D), cardiac death (CD), acute myocardial infarction (AMI), and stent thrombosis (ST) at 1 month were 1.1, 0.8, 0.1, and 0.5%, respectively, with no significant differences between groups. At 1 year, the death rate was 5.5% for Titan-2 vs. 4.1% for Optimax ® , CD was 1.8% for both groups, ST 1.1 vs. 0.6%, new AMI 3.3 vs. 2.5% and target lesion revascularization (TLR) 3.7 vs. 2.9%. The primary endpoint of the composite event (CE) of D/AMI/TLR/ST occurred in 10.3% vs. 7.6% (p = 0.211). Patients with STEACS (N = 322: Titan-2/Optimax: 103/209) had better outcomes for secondary events, device-oriented failure CD/AMI/TLR (7.8% vs. 5.0%; p = 0.330), and non-fatal CE of AMI/ST/TLR (7.8% vs. 2.7%, p = 0.039)., Conclusions: The Titan Optimax retains the efficacy and safety of Titan 2. It appears to perform better in the subgroup of STEACS patients, by reducing the non-fatal CE of AMI/ST/TLR., (© 2017 Wiley Periodicals, Inc.)